Math Formulae Page: 440 K-12 Formulas
A complete K-12 math formulae reference with 440 formulas across arithmetic, algebra, geometry, trigonometry, statistics, finance math, matrices, vectors, sets, and AP or IB calculus readiness.

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On This Page
Overview
This math formulae page turns the uploaded K-12 checklist into a complete reference: 440 formula entries across 26 topics. It starts with number sense, fractions, ratios, exponents, and algebra, then moves into coordinate geometry, 2D and 3D geometry, trigonometry, statistics, financial mathematics, matrices, vectors, logic, and calculus readiness.
The goal is not to make students memorize a wall of symbols. A formula page is useful when it helps you identify the right relationship, check units, substitute values carefully, and decide whether a calculator or graphing step should come next. For formula-heavy solving, pair this reference with the Math Equation Solver, Scientific Calculator, and topic-specific tools in the Math Calculators hub.
How To Use This Page
Start with the topic, not the formula name. If the problem is about a triangle, go to the triangle section before searching for an equation. If it is about a sequence, decide whether the pattern is arithmetic, geometric, recursive, finite, or infinite before substituting numbers.
Then read the "Use" column. Similar-looking formulas often answer different questions: circumference is distance around a circle, circle area is space inside the circle, arc length is part of the circumference, and sector area is part of the circle's area. In algebra, slope, average rate of change, secant slope, and difference quotient all look related, but they sit at different levels of precision.
Finally, check restrictions. Denominators cannot be zero, logarithm inputs must be positive, inverse functions require one-to-one behavior, geometric infinite series need |r| < 1, and many geometry formulas assume matching units. The table keeps those conditions short so the formula remains scannable. Each row also includes a variables/notation column so the symbols are defined beside the MathJax-rendered formula.
Educational Video
I looked for a credible supporting video from an educational or institutional source rather than embedding a random creator video. A suitable Khan Academy video exists for the foundation behind many geometry formulas, so it is embedded here as context before the complete formula list.
Formula Index
Use this index to jump to the right section. The full table below keeps the uploaded numbering from 1 through 440, so every item in the checklist has a matching formula entry.
1. Number Sense & Arithmetic (30 formulae)
| # | Formula name | Formula or rule | Variables / notation | Use |
|---|---|---|---|---|
| 1 | Place value formula | \[N=\sum_{i=0}^{k}d_i\times10^i\] |
| Break a number into digit values by powers of 10. |
| 2 | Expanded form formula | \[N=a_n10^n+\cdots+a_1\cdot10+a_0\] |
| Write a number as the sum of its place-value parts. |
| 3 | Standard form formula | \[N=\sum \text{place values}\] |
| Combine expanded place values into one ordinary numeral. |
| 4 | Rounding rule | \[\begin{gathered}\text{next digit >= 5 -> round up}\\\text{next digit < 5 -> keep}\end{gathered}\] |
| Round a value to a selected place. |
| 5 | Absolute value formula | \[|x|=\begin{cases}x,&x\ge0\\-x,&x<0\end{cases}\] |
| Find distance from zero without sign direction. |
| 6 | Additive inverse formula | \[a + (-a) = 0\] |
| Find the number that cancels a value under addition. |
| 7 | Multiplicative inverse formula | \[a\times\frac{1}{a}=1,\quad a\ne0\] |
| Find the reciprocal that cancels a value under multiplication. |
| 8 | Order of operations rule | \[\begin{gathered}\text{Parentheses -> exponents -> multiply/divide -> add/subtract}\end{gathered}\] |
| Evaluate expressions in the standard order. |
| 9 | Fraction addition formula | \[\frac{a}{b}+\frac{c}{d}=\frac{ad+bc}{bd}\] |
| Add fractions with unlike denominators. |
| 10 | Fraction subtraction formula | \[\frac{a}{b}-\frac{c}{d}=\frac{ad-bc}{bd}\] |
| Subtract fractions with unlike denominators. |
| 11 | Fraction multiplication formula | \[\frac{a}{b}\times\frac{c}{d}=\frac{ac}{bd}\] |
| Multiply numerators and denominators. |
| 12 | Fraction division formula | \[\frac{a/b}{c/d}=\frac{ad}{bc}\] |
| Divide by multiplying by the reciprocal. |
| 13 | Mixed number to improper fraction formula | \[a\frac{b}{c}=\frac{ac+b}{c}\] |
| Convert a whole-number-plus-fraction into one fraction. |
| 14 | Improper fraction to mixed number formula | \[\frac{a}{b}=q+\frac{r}{b},\quad a=bq+r\] |
| Separate an improper fraction into whole part and remainder. |
| 15 | Equivalent fractions formula | \[\frac{a}{b}=\frac{ak}{bk},\quad k\ne0\] |
| Create equal fractions by scaling numerator and denominator. |
| 16 | Simplifying fractions formula | \[\frac{a}{b}=\frac{a/g}{b/g},\quad g=\gcd(a,b)\] |
| Reduce a fraction to lowest terms. |
| 17 | Decimal to fraction conversion formula | \[\text{decimal}=\frac{\text{integer}}{10^n}\] |
| Convert a terminating decimal with n decimal places to a fraction. |
| 18 | Fraction to decimal conversion formula | \[a/b = a รท b\] |
| Convert a fraction by dividing numerator by denominator. |
| 19 | Percent to decimal conversion formula | \[p\%=\frac{p}{100}\] |
| Turn a percent into a decimal multiplier. |
| 20 | Decimal to percent conversion formula | \[\text{percent}=100\times\text{decimal}\] |
| Turn a decimal into a percent. |
| 21 | Fraction to percent conversion formula | \[\frac{a}{b}\times100\%\] |
| Convert a fraction into a percent. |
| 22 | Percent of a number formula | \[\text{part}=\frac{p}{100}\times\text{whole}\] |
| Find p percent of a quantity. |
| 23 | Percent increase formula | \[\text{new}=\text{original}\times\left(1+\frac{p}{100}\right)\] |
| Increase a value by p percent. |
| 24 | Percent decrease formula | \[\text{new}=\text{original}\times\left(1-\frac{p}{100}\right)\] |
| Decrease a value by p percent. |
| 25 | Percent change formula | \[\text{percent change}=\frac{\text{new}-\text{old}}{\text{old}}\times100\%\] |
| Measure relative change from an original value. |
| 26 | Ratio formula | \[a:b = a / b\] |
| Compare two quantities by division. |
| 27 | Proportion formula | \[\frac{a}{b}=\frac{c}{d}\Longrightarrow ad=bc\] |
| Solve equal-ratio problems by cross multiplication. |
| 28 | Unit rate formula | \[\text{unit rate}=\frac{\text{quantity}}{1\ \text{unit}}\] |
| Express a rate per one unit. |
| 29 | Average rate formula | \[\text{average rate}=\frac{\text{total change}}{\text{total time}}\] |
| Find one constant rate over an interval. |
| 30 | Scale factor formula | \[\text{scale factor}=\frac{\text{new length}}{\text{original length}}\] |
| Compare similar figures or resized quantities. |
2. Factors, Multiples & Number Theory (19 formulae)
| # | Formula name | Formula or rule | Variables / notation | Use |
|---|---|---|---|---|
| 31 | Divisibility rules | \[\begin{gathered}\text{n is divisible by d if n mod d = 0}\end{gathered}\] |
| Test whether division leaves no remainder. |
| 32 | Factor formula | \[n=a\times b\] |
| Identify numbers that multiply to make n. |
| 33 | Multiple formula | \[m=k\times n\] |
| Generate multiples of a number. |
| 34 | Prime factorization formula | \[n = p_1^{a} p_2^{b} ...\] |
| Write a number as powers of primes. |
| 35 | Greatest common factor formula | \[\begin{gathered}\text{gcf = product of common primes with smaller exponents}\end{gathered}\] |
| Find the largest shared factor. |
| 36 | Least common multiple formula | \[\operatorname{lcm}(a,b)=\frac{|ab|}{\gcd(a,b)}\] |
| Find the smallest shared multiple. |
| 37 | Euclidean algorithm formula | \[\gcd(a,b)=\gcd(b,a\bmod b)\] |
| Find a GCF by repeated remainders. |
| 38 | Exponent rules | \[a^m a^n=a^{m+n},\quad (a^m)^n=a^{mn}\] |
| Simplify powers with the same base. |
| 39 | Product of powers rule | \[a^m\times a^n=a^{m+n}\] |
| Multiply powers with the same base. |
| 40 | Quotient of powers rule | \[\frac{a^m}{a^n}=a^{m-n},\quad a\ne0\] |
| Divide powers with the same base. |
| 41 | Power of a power rule | \[(a^m)^n=a^{mn}\] |
| Raise one power to another power. |
| 42 | Power of a product rule | \[(ab)^n=a^n b^n\] |
| Distribute an exponent across multiplication. |
| 43 | Power of a quotient rule | \[\left(\frac{a}{b}\right)^n=\frac{a^n}{b^n},\quad b\ne0\] |
| Distribute an exponent across division. |
| 44 | Zero exponent rule | \[a^0=1,\quad a\ne0\] |
| Simplify any nonzero base raised to zero. |
| 45 | Negative exponent rule | \[a^{-n}=\frac{1}{a^n},\quad a\ne0\] |
| Rewrite negative exponents as reciprocals. |
| 46 | Scientific notation formula | \[N=a\times10^n,\quad 1\le |a|<10\] |
| Write very large or small numbers compactly. |
| 47 | Standard form to scientific notation formula | \[\text{move decimal }k\text{ places}\to a\times10^k\] |
| Convert an ordinary number to scientific notation. |
| 48 | Scientific notation multiplication rule | \[(a\times10^m)(b\times10^n)=ab\times10^{m+n}\] |
| Multiply numbers written in scientific notation. |
| 49 | Scientific notation division rule | \[\frac{a\times10^m}{b\times10^n}=\frac{a}{b}\times10^{m-n}\] |
| Divide numbers written in scientific notation. |
3. Integers & Rational Numbers (12 formulae)
| # | Formula name | Formula or rule | Variables / notation | Use |
|---|---|---|---|---|
| 50 | Integer addition rule | \[\begin{gathered}\text{same signs: add absolute values}\\\text{different signs: subtract absolute values}\end{gathered}\] |
| Add signed whole numbers. |
| 51 | Integer subtraction rule | \[a - b = a + (-b)\] |
| Turn subtraction into adding the opposite. |
| 52 | Integer multiplication rule | \[\begin{gathered}\text{(+)(+) = +, (-)(-) = +, (+)(-) = -}\end{gathered}\] |
| Choose the sign when multiplying integers. |
| 53 | Integer division rule | \[\begin{gathered}\text{same signs -> positive}\\\text{different signs -> negative}\end{gathered}\] |
| Choose the sign when dividing integers. |
| 54 | Rational number addition formula | \[\frac{a}{b}+\frac{c}{d}=\frac{ad+bc}{bd}\] |
| Add rational numbers as fractions. |
| 55 | Rational number subtraction formula | \[\frac{a}{b}-\frac{c}{d}=\frac{ad-bc}{bd}\] |
| Subtract rational numbers as fractions. |
| 56 | Rational number multiplication formula | \[\frac{a}{b}\times\frac{c}{d}=\frac{ac}{bd}\] |
| Multiply rational numbers. |
| 57 | Rational number division formula | \[\frac{a/b}{c/d}=\frac{ad}{bc},\quad c\ne0\] |
| Divide rational numbers. |
| 58 | Comparing rational numbers formula | \[a/b ? c/d by comparing ad ? bc\] |
| Compare fractions with positive denominators. |
| 59 | Ordering rational numbers rule | \[\begin{gathered}\text{use common denominators or decimal values}\end{gathered}\] |
| Place rational numbers from least to greatest. |
| 60 | Opposite numbers formula | \[a + (-a) = 0\] |
| Pair a number with its additive inverse. |
| 61 | Reciprocal formula | \[reciprocal of a = 1/a, a \ne 0\] |
| Find the multiplicative inverse. |
4. Algebra Basics (13 formulae)
| # | Formula name | Formula or rule | Variables / notation | Use |
|---|---|---|---|---|
| 62 | Variable expression formula | \[\begin{gathered}\text{expression value = expression after substituting variables}\end{gathered}\] |
| Represent unknown quantities with letters. |
| 63 | Algebraic expression evaluation formula | \[\begin{gathered}\text{if x = a, replace x with a and simplify}\end{gathered}\] |
| Evaluate an expression for given values. |
| 64 | Combining like terms rule | \[\begin{gathered}\text{ax + bx = (a + b)x}\end{gathered}\] |
| Combine terms with the same variable part. |
| 65 | Distributive property formula | \[a(b + c) = ab + ac\] |
| Multiply across a sum or difference. |
| 66 | Factoring common factor formula | \[ab + ac = a(b + c)\] |
| Pull out a shared factor. |
| 67 | One-step equation formula | \[x+a=b\Longrightarrow x=b-a,\quad ax=b\Longrightarrow x=\frac{b}{a}\] |
| Undo one operation to solve. |
| 68 | Two-step equation formula | \[ax+b=c\Longrightarrow x=\frac{c-b}{a}\] |
| Undo addition/subtraction, then multiplication/division. |
| 69 | Multi-step equation formula | \[\begin{gathered}\text{simplify both sides, then isolate x}\end{gathered}\] |
| Solve equations with combining, distributing, or repeated operations. |
| 70 | Literal equation rearrangement formula | \[\begin{gathered}\text{solve for target variable using inverse operations}\end{gathered}\] |
| Rearrange formulas for a different variable. |
| 71 | Inequality solving rule | \[\begin{gathered}\text{multiply/divide by a negative -> reverse inequality sign}\end{gathered}\] |
| Solve inequalities without losing order direction. |
| 72 | Compound inequality formula | \[\begin{gathered}\text{a < x < b or x < a OR x > b}\end{gathered}\] |
| Solve "and" and "or" inequality statements. |
| 73 | Absolute value equation formula | \[|x-a|=b\Longrightarrow x=a\pm b,\quad b\ge0\] |
| Solve equations involving distance from a center. |
| 74 | Absolute value inequality formula | \[\begin{gathered}|x-a|<b\Longrightarrow a-b<x<a+b\\|x-a|>b\Longrightarrow x<a-b\ \text{or}\ x>a+b\end{gathered}\] |
| Solve distance-bounded inequalities. |
5. Linear Equations & Functions (18 formulae)
| # | Formula name | Formula or rule | Variables / notation | Use |
|---|---|---|---|---|
| 75 | Slope formula | \[m=\frac{y_2-y_1}{x_2-x_1}\] |
| Find steepness from two points. |
| 76 | Slope-intercept form | \[y=mx+b\] |
| Write a line using slope and y-intercept. |
| 77 | Point-slope form | \[y-y_1=m(x-x_1)\] |
| Write a line from one point and slope. |
| 78 | Standard form of a line | \[Ax + By = C\] |
| Write a line with x and y terms on one side. |
| 79 | Two-point form of a line | \[y-y_1=\frac{y_2-y_1}{x_2-x_1}(x-x_1)\] |
| Write a line through two known points. |
| 80 | Horizontal line formula | \[y = c\] |
| Represent a line with zero slope. |
| 81 | Vertical line formula | \[x = c\] |
| Represent a line with undefined slope. |
| 82 | Parallel lines slope rule | \[m1 = m2\] |
| Check whether nonvertical lines are parallel. |
| 83 | Perpendicular lines slope rule | \[m_1m_2=-1\] |
| Check whether nonvertical lines meet at right angles. |
| 84 | x-intercept formula | \[\begin{gathered}\text{set y = 0 and solve for x}\end{gathered}\] |
| Find where a graph crosses the x-axis. |
| 85 | y-intercept formula | \[\begin{gathered}\text{set x = 0 and solve for y}\end{gathered}\] |
| Find where a graph crosses the y-axis. |
| 86 | Linear function formula | \[f(x) = mx + b\] |
| Model constant rate of change. |
| 87 | Direct variation formula | \[y = kx\] |
| Model proportional relationships. |
| 88 | Inverse variation formula | \[y = k/x\] |
| Model relationships where product xy is constant. |
| 89 | Constant rate of change formula | \[\begin{gathered}\text{rate = Delta y / Delta x}\end{gathered}\] |
| Measure equal change per input unit. |
| 90 | Arithmetic sequence formula | \[a_n=a_1+(n-1)d\] |
| Find the nth term of a linear sequence. |
| 91 | Arithmetic series formula | \[S_n=\frac{n}{2}(a_1+a_n)\] |
| Sum the first n terms of an arithmetic sequence. |
| 92 | Linear interpolation formula | \[y=y_1+\frac{(x-x_1)(y_2-y_1)}{x_2-x_1}\] |
| Estimate between two known points on a line. |
6. Systems of Equations (9 formulae)
| # | Formula name | Formula or rule | Variables / notation | Use |
|---|---|---|---|---|
| 93 | System of linear equations formula | \[a1x + b1y = c1; a2x + b2y = c2\] |
| Represent two linear equations solved together. |
| 94 | Substitution method formula | \[\begin{gathered}\text{solve one equation for a variable, then substitute into the other}\end{gathered}\] |
| Solve a system by replacing a variable expression. |
| 95 | Elimination method formula | \[\begin{gathered}\text{multiply equations so one variable cancels when added/subtracted}\end{gathered}\] |
| Solve a system by removing one variable. |
| 96 | Graphing method rule | \[\begin{gathered}\text{solution = intersection point(s)}\end{gathered}\] |
| Solve a system by graphing. |
| 97 | Determinant formula for 2x2 systems | \[D = ad - bc\] |
| Compute the determinant of [[a,b],[c,d]]. |
| 98 | Cramer's rule for 2x2 systems | \[x=\frac{D_x}{D},\quad y=\frac{D_y}{D}\] |
| Solve a 2-variable system using determinants. |
| 99 | Cramer's rule for 3x3 systems | \[x_i = \det(A_i) / \det(A)\] |
| Solve a 3-variable system using determinant replacement. |
| 100 | Matrix equation formula | \[Ax = b\] |
| Write a linear system in matrix form. |
| 101 | Matrix inverse solution formula | \[x = A^(-1)b\] |
| Solve an invertible matrix equation. |
7. Exponents, Radicals & Roots (11 formulae)
| # | Formula name | Formula or rule | Variables / notation | Use |
|---|---|---|---|---|
| 102 | Square root formula | \[\sqrt{x}=y\Longleftrightarrow y^2=x,\ y\ge0\] |
| Find the principal square root. |
| 103 | Cube root formula | \[\sqrt[3]{x}=y\Longleftrightarrow y^3=x\] |
| Find the number whose cube is x. |
| 104 | nth root formula | \[\sqrt[n]{x}=x^{1/n}\] |
| Rewrite roots as fractional exponents. |
| 105 | Radical simplification formula | \[\sqrt{ab} = \sqrt{a}\sqrt{b}\] |
| Separate perfect-square factors. |
| 106 | Radical multiplication rule | \[\sqrt{a}\sqrt{b} = \sqrt{ab}\] |
| Multiply compatible radicals. |
| 107 | Radical division rule | \[\sqrt{a}/\sqrt{b} = \sqrt{a/b}, b > 0\] |
| Divide compatible radicals. |
| 108 | Rational exponent formula | \[a^(m/n) = \sqrt[n]{a^{m}}\] |
| Connect exponents and roots. |
| 109 | Converting radicals to rational exponents | \[\sqrt[n]{a^{m}} = a^(m/n)\] |
| Rewrite radical notation as exponent notation. |
| 110 | Converting rational exponents to radicals | \[a^(m/n) = \sqrt[n]{a^{m}}\] |
| Rewrite exponent notation as radical notation. |
| 111 | Square root property | \[x^2=a\Longrightarrow x=\pm\sqrt{a}\] |
| Solve quadratic equations that are perfect squares. |
| 112 | Distance using square roots formula | \[d=\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}\] |
| Use the Pythagorean theorem on coordinate differences. |
8. Polynomials (17 formulae)
| # | Formula name | Formula or rule | Variables / notation | Use |
|---|---|---|---|---|
| 113 | Polynomial degree rule | \[\begin{gathered}\text{degree = highest exponent with nonzero coefficient}\end{gathered}\] |
| Identify polynomial degree. |
| 114 | Polynomial addition rule | \[(\sum a_i x^{i}) + (\sum b_i x^{i}) = \sum(a_i + b_i)x^{i}\] |
| Add like polynomial terms. |
| 115 | Polynomial subtraction rule | \[P(x) - Q(x) = P(x) + (-Q(x))\] |
| Subtract by distributing the negative. |
| 116 | Polynomial multiplication rule | \[(\sum a_i x^{i})(\sum b_j x^{j}) = \sum a_i b_j x^(i+j)\] |
| Multiply every term by every term. |
| 117 | Monomial multiplication formula | \[(ax^{m})(bx^{n}) = ab x^(m+n)\] |
| Multiply one-term expressions. |
| 118 | Binomial multiplication formula | \[(a + b)(c + d) = ac + ad + bc + bd\] |
| Multiply two binomials. |
| 119 | FOIL formula | \[(a + b)(c + d) = ac + ad + bc + bd\] |
| Use first, outer, inner, last for binomials. |
| 120 | Special product: square of a binomial | \[(a\pm b)^2=a^2\pm2ab+b^2\] |
| Expand a binomial square. |
| 121 | Special product: difference of squares | \[(a-b)(a+b)=a^2-b^2\] |
| Factor or expand conjugates. |
| 122 | Special product: sum of cubes | \[a^3+b^3=(a+b)(a^2-ab+b^2)\] |
| Factor a sum of cubes. |
| 123 | Special product: difference of cubes | \[a^3-b^3=(a-b)(a^2+ab+b^2)\] |
| Factor a difference of cubes. |
| 124 | Factoring trinomials formula | \[x^{2} + bx + c = (x + m)(x + n), m + n = b, mn = c\] |
| Factor simple quadratic trinomials. |
| 125 | Factoring by grouping formula | \[ax + ay + bx + by = (a + b)(x + y)\] |
| Factor four-term expressions by pairs. |
| 126 | Remainder theorem | \[\begin{gathered}\text{remainder when P(x) is divided by x - a is P(a)}\end{gathered}\] |
| Find a division remainder without dividing. |
| 127 | Factor theorem | \[x - a is a factor of P(x) \Longleftrightarrow P(a) = 0\] |
| Connect zeros and linear factors. |
| 128 | Polynomial long division formula | \[P(x) = D(x)Q(x) + R(x)\] |
| Divide polynomials with quotient and remainder. |
| 129 | Synthetic division formula | \[\begin{gathered}\text{use coefficients with root a for divisor x - a}\end{gathered}\] |
| Shortcut division by a linear divisor. |
9. Quadratic Equations & Functions (14 formulae)
| # | Formula name | Formula or rule | Variables / notation | Use |
|---|---|---|---|---|
| 130 | Standard form of a quadratic | \[y = ax^{2} + bx + c\] |
| Write a quadratic by coefficients. |
| 131 | Vertex form of a quadratic | \[y = a(x - h)^{2} + k\] |
| Write a quadratic by vertex and stretch. |
| 132 | Factored form of a quadratic | \[y = a(x - r1)(x - r2)\] |
| Write a quadratic by roots. |
| 133 | Quadratic formula | \[x=\frac{-b\pm\sqrt{b^2-4ac}}{2a}\] |
| Solve ax^2 + bx + c = 0. |
| 134 | Discriminant formula | \[D=b^2-4ac\] |
| Determine the type and number of roots. |
| 135 | Axis of symmetry formula | \[x=-\frac{b}{2a}\] |
| Find the vertical symmetry line. |
| 136 | Vertex formula | \[h = -b/(2a), k = f(h)\] |
| Find the vertex from standard form. |
| 137 | Completing the square formula | \[x^2+bx=\left(x+\frac{b}{2}\right)^2-\left(\frac{b}{2}\right)^2\] |
| Rewrite a quadratic as a square plus constant. |
| 138 | Sum of roots formula | \[r1 + r2 = -b/a\] |
| Use Vieta relations for a quadratic. |
| 139 | Product of roots formula | \[r1 r2 = c/a\] |
| Use Vieta relations for a quadratic. |
| 140 | Maximum value of a quadratic formula | \[\begin{gathered}\text{max = k when a < 0 in y = a(x - h)\^{}2 + k}\end{gathered}\] |
| Find peak value of a downward-opening parabola. |
| 141 | Minimum value of a quadratic formula | \[\begin{gathered}\text{min = k when a > 0 in y = a(x - h)\^{}2 + k}\end{gathered}\] |
| Find lowest value of an upward-opening parabola. |
| 142 | Parabola opening rule | \[\begin{gathered}\text{a > 0 opens up}\\\text{a < 0 opens down}\end{gathered}\] |
| Read direction from the leading coefficient. |
| 143 | Quadratic regression formula | \[y = ax^{2} + bx + c\] |
| Fit a quadratic model to data. |
10. Functions (16 formulae)
| # | Formula name | Formula or rule | Variables / notation | Use |
|---|---|---|---|---|
| 144 | Function notation formula | \[y = f(x)\] |
| Name an output rule by its input. |
| 145 | Domain rule | \[\begin{gathered}\text{domain = all allowed input values x}\end{gathered}\] |
| State the inputs for which a function is defined. |
| 146 | Range rule | \[\begin{gathered}\text{range = \{f(x): x in domain\}}\end{gathered}\] |
| State all possible outputs. |
| 147 | Composite function formula | \[(f\circ g)(x)=f(g(x))\] |
| Apply one function inside another. |
| 148 | Inverse function formula | \[f^(-1)(f(x)) = x\] |
| Reverse a one-to-one function. |
| 149 | Even function rule | \[\begin{gathered}\text{f(-x) = f(x)}\end{gathered}\] |
| Test y-axis symmetry. |
| 150 | Odd function rule | \[\begin{gathered}\text{f(-x) = -f(x)}\end{gathered}\] |
| Test origin symmetry. |
| 151 | Piecewise function formula | \[\begin{gathered}\text{f(x) = case rule by interval}\end{gathered}\] |
| Use different rules on different domains. |
| 152 | Function transformation formulas | \[\begin{gathered}\text{y = a f(b(x - h)) + k}\end{gathered}\] |
| Combine shifts, reflections, stretches, and compressions. |
| 153 | Horizontal shift formula | \[y = f(x - h)\] |
| Move a graph right h units when h is positive. |
| 154 | Vertical shift formula | \[y = f(x) + k\] |
| Move a graph up k units when k is positive. |
| 155 | Reflection formula | \[\begin{gathered}\text{y = -f(x) reflects over x-axis}\\\text{y = f(-x) reflects over y-axis}\end{gathered}\] |
| Flip a graph across an axis. |
| 156 | Stretch formula | \[\begin{gathered}\text{y = a f(x), |a| > 1}\end{gathered}\] |
| Stretch outputs vertically. |
| 157 | Compression formula | \[\begin{gathered}\text{y = a f(x), 0 < |a| < 1}\end{gathered}\] |
| Compress outputs vertically. |
| 158 | Average rate of change formula | \[\frac{f(b)-f(a)}{b-a}\] |
| Find average change over an interval. |
| 159 | Difference quotient formula | \[\frac{f(x+h)-f(x)}{h}\] |
| Measure a function change over input step h. |
11. Exponential & Logarithmic Functions (15 formulae)
| # | Formula name | Formula or rule | Variables / notation | Use |
|---|---|---|---|---|
| 160 | Exponential growth formula | \[y = a(1 + r)^{t}\] |
| Model growth by a fixed percent rate. |
| 161 | Exponential decay formula | \[y = a(1 - r)^{t}\] |
| Model decay by a fixed percent rate. |
| 162 | General exponential function formula | \[y = ab^{x}\] |
| Model repeated multiplication by base b. |
| 163 | Compound interest formula | \[A=P\left(1+\frac{r}{n}\right)^{nt}\] |
| Calculate interest compounded n times per year. |
| 164 | Continuously compounded interest formula | \[A=Pe^{rt}\] |
| Calculate interest compounded continuously. |
| 165 | Half-life formula | \[A = A0(1/2)^(t/h)\] |
| Model decay by repeated halving. |
| 166 | Doubling time formula | \[T = \ln(2) / k for y = ae^(kt)\] |
| Find time needed to double under continuous growth. |
| 167 | Logarithmic form formula | \[y = log_b(x)\] |
| Write the exponent needed to make x from base b. |
| 168 | Exponential form formula | \[b^y=x\Longleftrightarrow y=\log_b(x)\] |
| Convert between log and exponential form. |
| 169 | Product rule of logarithms | \[log_b(MN) = log_b(M) + log_b(N)\] |
| Expand the log of a product. |
| 170 | Quotient rule of logarithms | \[log_b(M/N) = log_b(M) - log_b(N)\] |
| Expand the log of a quotient. |
| 171 | Power rule of logarithms | \[log_b(M^{p}) = p log_b(M)\] |
| Move an exponent out of a logarithm. |
| 172 | Change of base formula | \[\log_b(x)=\frac{\ln x}{\ln b}\] |
| Evaluate logs with a different base. |
| 173 | Natural logarithm formula | \[\ln(x) = log_e(x)\] |
| Use base e logarithms. |
| 174 | Common logarithm formula | \[\log(x) = log_10(x)\] |
| Use base 10 logarithms. |
12. Sequences & Series (11 formulae)
| # | Formula name | Formula or rule | Variables / notation | Use |
|---|---|---|---|---|
| 175 | Arithmetic sequence nth-term formula | \[a_n=a_1+(n-1)d\] |
| Find a term in an arithmetic sequence. |
| 176 | Arithmetic series sum formula | \[S_n=\frac{n}{2}\left(2a_1+(n-1)d\right)\] |
| Sum the first n arithmetic terms. |
| 177 | Geometric sequence nth-term formula | \[a_n=a_1r^{n-1}\] |
| Find a term in a geometric sequence. |
| 178 | Geometric series sum formula | \[S_n=\frac{a_1(1-r^n)}{1-r},\quad r\ne1\] |
| Sum the first n geometric terms. |
| 179 | Infinite geometric series formula | \[S=\frac{a_1}{1-r},\quad |r|<1\] |
| Sum an infinite geometric series that converges. |
| 180 | Recursive sequence formula | \[\begin{gathered}\text{a\_n = f(a\_(n-1)), with starting value a\_1}\end{gathered}\] |
| Define each term from earlier term(s). |
| 181 | Fibonacci sequence formula | \[F_n = F_(n-1) + F_(n-2), F_1 = 1, F_2 = 1\] |
| Generate Fibonacci terms recursively. |
| 182 | Sigma notation formula | \[\sum_{i=m}^{n} a_i\] |
| Write repeated addition compactly. |
| 183 | Partial sum formula | \[S_n = \sum_{i=1}^{n} a_i\] |
| Add the first n terms of a sequence. |
| 184 | Finite series formula | \[S_n = a_1 + a_2 + ... + a_n\] |
| Represent a series with finitely many terms. |
| 185 | Infinite series formula | \[S = \lim(n \to \infty) S_n\] |
| Define an infinite series by a limit of partial sums. |
13. Coordinate Geometry (15 formulae)
| # | Formula name | Formula or rule | Variables / notation | Use |
|---|---|---|---|---|
| 186 | Distance formula | \[d=\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}\] |
| Find distance between two points. |
| 187 | Midpoint formula | \[M=\left(\frac{x_1+x_2}{2},\frac{y_1+y_2}{2}\right)\] |
| Find the point halfway between two points. |
| 188 | Section formula | \[P = ((mx2 + nx1)/(m+n), (my2 + ny1)/(m+n))\] |
| Find a point dividing a segment in ratio m:n. |
| 189 | Slope formula | \[m = (y2 - y1)/(x2 - x1)\] |
| Find steepness between two points. |
| 190 | Equation of a line | \[y - y1 = m(x - x1)\] |
| Write a line through a point with slope m. |
| 191 | Equation of a circle | \[(x - h)^{2} + (y - k)^{2} = r^{2}\] |
| Write a circle by center and radius. |
| 192 | Center-radius form of a circle | \[(x - h)^{2} + (y - k)^{2} = r^{2}\] |
| Read center (h,k) and radius r. |
| 193 | General form of a circle | \[x^{2} + y^{2} + Dx + Ey + F = 0\] |
| Write a circle after expansion. |
| 194 | Equation of a parabola | \[(x - h)^{2} = 4p(y - k) or (y - k)^{2} = 4p(x - h)\] |
| Represent a parabola by vertex and focus distance. |
| 195 | Equation of an ellipse | \[(x - h)^{2}/a^{2} + (y - k)^{2}/b^{2} = 1\] |
| Represent an axis-aligned ellipse. |
| 196 | Equation of a hyperbola | \[(x - h)^{2}/a^{2} - (y - k)^{2}/b^{2} = 1\] |
| Represent a horizontal axis-aligned hyperbola. |
| 197 | Translation formula | \[(x, y) \to (x + a, y + b)\] |
| Move a point by vector (a,b). |
| 198 | Reflection formula | \[\begin{gathered}\text{over x-axis: (x,y)->(x,-y)}\\\text{over y-axis: (x,y)->(-x,y)}\end{gathered}\] |
| Reflect a point across an axis. |
| 199 | Rotation formula | \[\begin{gathered}\text{x' = x cos theta - y sin theta}\\\text{y' = x sin theta + y cos theta}\end{gathered}\] |
| Rotate a point about the origin. |
| 200 | Dilation formula | \[(x, y) \to (kx, ky)\] |
| Scale a point from the origin by factor k. |
14. Basic Geometry (16 formulae)
| # | Formula name | Formula or rule | Variables / notation | Use |
|---|---|---|---|---|
| 201 | Point formula | \[\begin{gathered}\text{point = (x, y)}\end{gathered}\] |
| Represent a location with coordinates. |
| 202 | Line formula | \[\begin{gathered}\text{Ax + By + C = 0}\end{gathered}\] |
| Represent a straight line in general form. |
| 203 | Ray formula | \[\begin{gathered}\text{R(t) = P + tv, t >= 0}\end{gathered}\] |
| Represent a ray from endpoint P in direction v. |
| 204 | Line segment formula | \[length = \sqrt{(x2 - x1)^{2} + (y2 - y1)^{2}}\] |
| Find the length of a segment. |
| 205 | Angle sum formula | \[\begin{gathered}\text{angles on a line = 180ยฐ}\\\text{angles around a point = 360ยฐ}\end{gathered}\] |
| Use standard angle totals. |
| 206 | Complementary angles formula | \[A + B = 90ยฐ\] |
| Relate two angles that make a right angle. |
| 207 | Supplementary angles formula | \[A + B = 180ยฐ\] |
| Relate two angles that make a straight angle. |
| 208 | Vertical angles rule | \[\begin{gathered}\text{vertical angles are equal}\end{gathered}\] |
| Use opposite angles formed by intersecting lines. |
| 209 | Linear pair rule | \[\begin{gathered}\text{adjacent linear-pair angles sum to 180ยฐ}\end{gathered}\] |
| Use angles sharing a straight line. |
| 210 | Triangle angle sum formula | \[A+B+C=180^\circ\] |
| Find missing angles in triangles. |
| 211 | Exterior angle theorem | \[\begin{gathered}\text{exterior angle = sum of two remote interior angles}\end{gathered}\] |
| Relate a triangle exterior angle to interior angles. |
| 212 | Polygon interior angle sum formula | \[\text{sum}=(n-2)180^\circ\] |
| Find total interior angle measure. |
| 213 | Polygon exterior angle sum formula | \[\sum = 360ยฐ\] |
| Find total exterior angle measure for a convex polygon. |
| 214 | Regular polygon interior angle formula | \[\text{each interior angle}=\frac{(n-2)180^\circ}{n}\] |
| Find one angle in a regular polygon. |
| 215 | Regular polygon exterior angle formula | \[each exterior angle = 360ยฐ/n\] |
| Find one exterior angle in a regular polygon. |
| 216 | Diagonal formula for polygons | \[\text{diagonals}=\frac{n(n-3)}{2}\] |
| Count diagonals in an n-sided polygon. |
15. Triangles (16 formulae)
| # | Formula name | Formula or rule | Variables / notation | Use |
|---|---|---|---|---|
| 217 | Triangle perimeter formula | \[P = a + b + c\] |
| Add all three side lengths. |
| 218 | Triangle area formula | \[A=\frac{1}{2}bh\] |
| Find area from base and height. |
| 219 | Right triangle area formula | \[A = (1/2)(leg1)(leg2)\] |
| Use perpendicular legs as base and height. |
| 220 | Equilateral triangle area formula | \[A=\frac{\sqrt{3}}{4}s^2\] |
| Find area from side length s. |
| 221 | Heron's formula | \[A=\sqrt{s(s-a)(s-b)(s-c)},\quad s=\frac{a+b+c}{2}\] |
| Find triangle area from three sides. |
| 222 | Pythagorean theorem | \[a^2+b^2=c^2\] |
| Relate legs and hypotenuse in a right triangle. |
| 223 | Converse of Pythagorean theorem | \[\begin{gathered}\text{if a\^{}2 + b\^{}2 = c\^{}2, triangle is right}\end{gathered}\] |
| Test whether side lengths form a right triangle. |
| 224 | Special right triangle 45-45-90 formulas | \[x,\ x,\ x\sqrt{2}\] |
| Use side ratios for an isosceles right triangle. |
| 225 | Special right triangle 30-60-90 formulas | \[x,\ x\sqrt{3},\ 2x\] |
| Use side ratios opposite 30ยฐ, 60ยฐ, and 90ยฐ. |
| 226 | Triangle inequality theorem | \[a + b > c, a + c > b, b + c > a\] |
| Check whether three sides can form a triangle. |
| 227 | Similar triangles proportion formula | \[\begin{gathered}\text{a/b = c/d = scale factor}\end{gathered}\] |
| Relate corresponding sides in similar triangles. |
| 228 | Congruent triangles rules | \[\begin{gathered}\text{SSS, SAS, ASA, AAS, HL}\end{gathered}\] |
| Prove triangles have matching size and shape. |
| 229 | Median formula | \[m_a = (1/2)\sqrt{2b^{2} + 2c^{2} - a^{2}}\] |
| Find the median to side a. |
| 230 | Altitude formula | \[h = 2A / b\] |
| Find height from area and base. |
| 231 | Angle bisector theorem | \[BD/DC = AB/AC\] |
| Relate side split by an angle bisector. |
| 232 | Perpendicular bisector theorem | \[\begin{gathered}\text{if P is on perpendicular bisector of AB, PA = PB}\end{gathered}\] |
| Use equal distances from segment endpoints. |
16. Quadrilaterals (16 formulae)
| # | Formula name | Formula or rule | Variables / notation | Use |
|---|---|---|---|---|
| 233 | Square perimeter formula | \[P = 4s\] |
| Find square perimeter from side length. |
| 234 | Square area formula | \[A = s^{2}\] |
| Find square area from side length. |
| 235 | Rectangle perimeter formula | \[P=2(l+w)\] |
| Find rectangle perimeter. |
| 236 | Rectangle area formula | \[A=lw\] |
| Find rectangle area. |
| 237 | Parallelogram perimeter formula | \[P = 2(a + b)\] |
| Find perimeter from adjacent side lengths. |
| 238 | Parallelogram area formula | \[A = bh\] |
| Find area from base and height. |
| 239 | Rhombus perimeter formula | \[P = 4s\] |
| Find rhombus perimeter. |
| 240 | Rhombus area formula | \[A=\frac{d_1d_2}{2}\] |
| Find rhombus area from diagonals. |
| 241 | Trapezoid area formula | \[A=\frac{1}{2}(b_1+b_2)h\] |
| Find trapezoid area from bases and height. |
| 242 | Kite area formula | \[A = (d1 d2)/2\] |
| Find kite area from diagonals. |
| 243 | Diagonal formula of rectangle | \[d = \sqrt{l^{2} + w^{2}}\] |
| Find a rectangle diagonal. |
| 244 | Diagonal formula of square | \[d = s \sqrt{2}\] |
| Find a square diagonal. |
| 245 | Properties of parallelograms formulas | \[\begin{gathered}\text{opposite sides equal}\\\text{opposite angles equal}\\\text{diagonals bisect}\end{gathered}\] |
| Use core parallelogram relationships. |
| 246 | Properties of rectangles formulas | \[\begin{gathered}\text{all angles = 90ยฐ}\\\text{d\^{}2 = l\^{}2 + w\^{}2}\end{gathered}\] |
| Use rectangle angle and diagonal facts. |
| 247 | Properties of rhombuses formulas | \[\begin{gathered}\text{all sides equal}\\\text{diagonals are perpendicular}\\\text{A = d1d2/2}\end{gathered}\] |
| Use rhombus side and diagonal facts. |
| 248 | Properties of squares formulas | \[\begin{gathered}\text{P = 4s}\\\text{A = s\^{}2}\\\text{d = s sqrt(2)}\end{gathered}\] |
| Use square side, area, and diagonal facts. |
17. Circles (14 formulae)
| # | Formula name | Formula or rule | Variables / notation | Use |
|---|---|---|---|---|
| 249 | Circle circumference formula | \[C=2\pi r=\pi d\] |
| Find distance around a circle. |
| 250 | Circle area formula | \[A=\pi r^2\] |
| Find area inside a circle. |
| 251 | Radius formula | \[r = d/2 = C/(2pi)\] |
| Find radius from diameter or circumference. |
| 252 | Diameter formula | \[d = 2r = C/\pi\] |
| Find diameter from radius or circumference. |
| 253 | Arc length formula | \[s=r\theta\] |
| Find arc length when theta is in radians. |
| 254 | Sector area formula | \[A=\frac{1}{2}r^2\theta\] |
| Find sector area when theta is in radians. |
| 255 | Segment area formula | \[A = (r^{2}/2)(\theta - \sin \theta)\] |
| Find area between chord and arc. |
| 256 | Central angle formula | \[\theta = s/r\] |
| Find central angle from arc length and radius. |
| 257 | Inscribed angle formula | \[inscribed angle = (1/2)(intercepted arc)\] |
| Relate an inscribed angle to its arc. |
| 258 | Chord length formula | \[chord = 2r \sin(\theta/2)\] |
| Find chord length from radius and central angle. |
| 259 | Tangent length formula | \[PA = PB\] |
| Use equal tangent lengths from the same external point. |
| 260 | Secant-tangent theorem | \[\text{tangent}^2=(\text{external secant})(\text{whole secant})\] |
| Solve tangent and secant lengths. |
| 261 | Intersecting chords theorem | \[a\times b=c\times d\] |
| Use products of chord segments inside a circle. |
| 262 | Circle equation formula | \[(x - h)^{2} + (y - k)^{2} = r^{2}\] |
| Graph a circle in the coordinate plane. |
18. Three-Dimensional Geometry (19 formulae)
| # | Formula name | Formula or rule | Variables / notation | Use |
|---|---|---|---|---|
| 263 | Cube volume formula | \[V = s^{3}\] |
| Find volume from cube side length. |
| 264 | Cube surface area formula | \[SA = 6s^{2}\] |
| Find total area of six square faces. |
| 265 | Rectangular prism volume formula | \[V = lwh\] |
| Find box volume. |
| 266 | Rectangular prism surface area formula | \[SA = 2(lw + lh + wh)\] |
| Find total area of a rectangular prism. |
| 267 | Triangular prism volume formula | \[V=(\text{area of triangular base})\times\text{length}\] |
| Find volume of a triangular prism. |
| 268 | Prism surface area formula | \[SA = 2B + Ph\] |
| Find surface area from base area B and base perimeter P. |
| 269 | Cylinder volume formula | \[V=\pi r^2h\] |
| Find cylinder volume. |
| 270 | Cylinder surface area formula | \[SA = 2pi r^{2} + 2pi rh\] |
| Find total cylinder surface area. |
| 271 | Cone volume formula | \[V = (1/3)\pi r^{2} h\] |
| Find cone volume. |
| 272 | Cone surface area formula | \[SA = \pi r^{2} + \pi r l\] |
| Find total cone surface area with slant height l. |
| 273 | Sphere volume formula | \[V=\frac{4}{3}\pi r^3\] |
| Find sphere volume. |
| 274 | Sphere surface area formula | \[SA = 4pi r^{2}\] |
| Find sphere surface area. |
| 275 | Hemisphere volume formula | \[V = (2/3)\pi r^{3}\] |
| Find half-sphere volume. |
| 276 | Hemisphere surface area formula | \[\begin{gathered}\text{SA = 3pi r\^{}2 total}\\\text{curved area = 2pi r\^{}2}\end{gathered}\] |
| Find total or curved hemisphere surface area. |
| 277 | Pyramid volume formula | \[V = (1/3)Bh\] |
| Find pyramid volume from base area and height. |
| 278 | Pyramid surface area formula | \[SA = B + (1/2)Pl\] |
| Find pyramid surface area with slant height l. |
| 279 | Frustum volume formula | \[V = (h/3)(A1 + A2 + \sqrt{A1A2})\] |
| Find volume between two similar parallel bases. |
| 280 | Composite solid volume formula | \[V_total = \sum V_parts - \sum V_removed\] |
| Combine volumes of multiple solids. |
| 281 | Density formula | \[\rho = m / V\] |
| Relate mass and volume. |
19. Measurement (12 formulae)
| # | Formula name | Formula or rule | Variables / notation | Use |
|---|---|---|---|---|
| 282 | Length conversion formulas | \[\begin{gathered}\text{new length = old length x conversion factor}\end{gathered}\] |
| Convert between length units. |
| 283 | Area conversion formulas | \[\begin{gathered}\text{new area = old area x (linear factor)\^{}2}\end{gathered}\] |
| Convert between area units. |
| 284 | Volume conversion formulas | \[\begin{gathered}\text{new volume = old volume x (linear factor)\^{}3}\end{gathered}\] |
| Convert between volume units. |
| 285 | Mass conversion formulas | \[\begin{gathered}\text{new mass = old mass x conversion factor}\end{gathered}\] |
| Convert between mass units. |
| 286 | Time conversion formulas | \[\begin{gathered}\text{new time = old time x conversion factor}\end{gathered}\] |
| Convert seconds, minutes, hours, days, and years. |
| 287 | Temperature conversion formulas | \[F = (9/5)C + 32; C = (5/9)(F - 32); K = C + 273.15\] |
| Convert Celsius, Fahrenheit, and Kelvin. |
| 288 | Speed formula | \[speed = distance / time\] |
| Measure how fast distance is covered. |
| 289 | Distance formula | \[\begin{gathered}\text{distance = rate x time}\end{gathered}\] |
| Find distance from rate and time. |
| 290 | Time formula | \[\begin{gathered}\text{time = distance / rate}\end{gathered}\] |
| Find time from distance and rate. |
| 291 | Rate formula | \[\begin{gathered}\text{rate = quantity / time}\end{gathered}\] |
| Find change per unit time. |
| 292 | Unit conversion formula | \[\begin{gathered}\text{converted value = original value x unit ratio}\end{gathered}\] |
| Convert units using a factor equal to 1. |
| 293 | Dimensional analysis formula | \[\begin{gathered}\text{value x (desired unit / given unit)}\end{gathered}\] |
| Cancel units to check a conversion path. |
20. Trigonometry (20 formulae)
| # | Formula name | Formula or rule | Variables / notation | Use |
|---|---|---|---|---|
| 294 | Sine ratio formula | \[\sin\theta=\frac{\text{opposite}}{\text{hypotenuse}}\] |
| Find sine in a right triangle. |
| 295 | Cosine ratio formula | \[\cos\theta=\frac{\text{adjacent}}{\text{hypotenuse}}\] |
| Find cosine in a right triangle. |
| 296 | Tangent ratio formula | \[\tan\theta=\frac{\text{opposite}}{\text{adjacent}}\] |
| Find tangent in a right triangle. |
| 297 | Reciprocal trigonometric ratios | \[\begin{gathered}\text{csc theta = 1/sin theta}\\\text{sec theta = 1/cos theta}\\\text{cot theta = 1/tan theta}\end{gathered}\] |
| Use reciprocal trig functions. |
| 298 | Pythagorean trigonometric identity | \[\sin^2\theta+\cos^2\theta=1\] |
| Simplify trig expressions. |
| 299 | Complementary angle identities | \[\begin{gathered}\text{sin(90ยฐ - theta) = cos theta}\\\text{tan(90ยฐ - theta) = cot theta}\end{gathered}\] |
| Relate cofunctions of complementary angles. |
| 300 | Unit circle formulas | \[(x, y) = (\cos \theta, \sin \theta)\] |
| Read sine and cosine from a unit-circle point. |
| 301 | Radian measure formula | \[\theta = s/r\] |
| Define radians from arc length and radius. |
| 302 | Degree-radian conversion formula | \[\text{radians}=\text{degrees}\times\frac{\pi}{180}\] |
| Convert angle units. |
| 303 | Arc length using radians formula | \[s = r \theta\] |
| Find arc length with theta in radians. |
| 304 | Sector area using radians formula | \[A = (1/2)r^{2} \theta\] |
| Find sector area with theta in radians. |
| 305 | Law of sines | \[\frac{a}{\sin A}=\frac{b}{\sin B}=\frac{c}{\sin C}\] |
| Solve non-right triangles with side-angle pairs. |
| 306 | Law of cosines | \[c^2=a^2+b^2-2ab\cos C\] |
| Solve non-right triangles with included angle or three sides. |
| 307 | Area of triangle using sine formula | \[A = (1/2)ab \sin C\] |
| Find triangle area from two sides and included angle. |
| 308 | Sum identities | \[\sin(a+b)=\sin a \cos b + \cos a \sin b; \cos(a+b)=\cos a \cos b - \sin a \sin b\] |
| Expand trig functions of sums. |
| 309 | Difference identities | \[\sin(a-b)=\sin a \cos b - \cos a \sin b; \cos(a-b)=\cos a \cos b + \sin a \sin b\] |
| Expand trig functions of differences. |
| 310 | Double-angle identities | \[\sin 2x = 2sin x \cos x; \cos 2x = \cos^{2} x - \sin^{2} x\] |
| Simplify trig expressions with twice an angle. |
| 311 | Half-angle identities | \[\sin^{2}(x/2) = (1 - \cos x)/2; \cos^{2}(x/2) = (1 + \cos x)/2\] |
| Work with half-angle expressions. |
| 312 | Inverse trigonometric formulas | \[\theta = \sin^(-1)(x), \cos^(-1)(x), or \tan^(-1)(x)\] |
| Find an angle from a trig ratio. |
| 313 | Trigonometric equation formulas | \[\sin x = a \to x = \arcsin(a) + 2pi k or \pi - \arcsin(a) + 2pi k\] |
| Write general solutions for trig equations. |
21. Data, Statistics & Probability (33 formulae)
| # | Formula name | Formula or rule | Variables / notation | Use |
|---|---|---|---|---|
| 314 | Mean formula | \[\bar{x}=\frac{\sum x_i}{n}\] |
| Find the arithmetic average. |
| 315 | Median formula | \[\begin{gathered}\text{median = middle ordered value}\end{gathered}\] |
| Find the center of ordered data. |
| 316 | Mode formula | \[\begin{gathered}\text{mode = most frequent value}\end{gathered}\] |
| Find the most repeated value. |
| 317 | Range formula | \[range = maximum - minimum\] |
| Measure spread from smallest to largest. |
| 318 | Interquartile range formula | \[\operatorname{IQR}=Q_3-Q_1\] |
| Measure spread of the middle half. |
| 319 | Quartile formula | \[Q_k position = k(n + 1)/4\] |
| Estimate quartile positions in ordered data. |
| 320 | Percentile formula | \[\text{percentile rank}=\frac{\text{values below}}{n}\times100\] |
| Measure relative standing in data. |
| 321 | Mean absolute deviation formula | \[MAD = (\sum |x_i - mean|) / n\] |
| Measure average absolute distance from the mean. |
| 322 | Variance formula | \[\begin{gathered}\text{variance = mean of squared deviations}\end{gathered}\] |
| Measure average squared spread. |
| 323 | Standard deviation formula | \[\begin{gathered}\text{standard deviation = sqrt(variance)}\end{gathered}\] |
| Measure typical distance from the mean. |
| 324 | Population variance formula | \[\sigma^2=\frac{\sum(x_i-\mu)^2}{N}\] |
| Find variance for a full population. |
| 325 | Sample variance formula | \[s^2=\frac{\sum(x_i-\bar{x})^2}{n-1}\] |
| Estimate variance from a sample. |
| 326 | Population standard deviation formula | \[\sigma = \sqrt{(\sum (x_i - \mu)^{2}) / N}\] |
| Find population standard deviation. |
| 327 | Sample standard deviation formula | \[s = \sqrt{(\sum (x_i - xbar)^{2}) / (n - 1)}\] |
| Find sample standard deviation. |
| 328 | z-score formula | \[z=\frac{x-\mu}{\sigma}\] |
| Measure standard deviations from the mean. |
| 329 | Weighted mean formula | \[\bar{x}_w=\frac{\sum w_ix_i}{\sum w_i}\] |
| Average values with weights. |
| 330 | Frequency table formula | \[\begin{gathered}\text{N = sum f\_i}\end{gathered}\] |
| Summarize counts by category or value. |
| 331 | Relative frequency formula | \[relative frequency = f / N\] |
| Convert a count to a share. |
| 332 | Probability formula | \[P(E)=\frac{\text{favorable outcomes}}{\text{total outcomes}}\] |
| Find basic probability. |
| 333 | Experimental probability formula | \[P(E) = successes / trials\] |
| Estimate probability from results. |
| 334 | Theoretical probability formula | \[\begin{gathered}\text{P(E) = favorable equally likely outcomes / all equally likely outcomes}\end{gathered}\] |
| Find probability from a model. |
| 335 | Complement probability formula | \[P(not E) = 1 - P(E)\] |
| Find the probability an event does not occur. |
| 336 | Addition rule of probability | \[P(A \cup B) = P(A) + P(B) - P(A \cap B)\] |
| Find probability of A or B. |
| 337 | Multiplication rule of probability | \[P(A \cap B) = P(A)P(B|A)\] |
| Find probability of A and B. |
| 338 | Conditional probability formula | \[P(A\mid B)=\frac{P(A\cap B)}{P(B)}\] |
| Find probability of A given B. |
| 339 | Independent events formula | \[P(A \cap B) = P(A)P(B)\] |
| Test or use independence. |
| 340 | Dependent events formula | \[\begin{gathered}\text{P(A then B) = P(A)P(B|A)}\end{gathered}\] |
| Handle probability when the first event changes the second. |
| 341 | Mutually exclusive events formula | \[P(A \cap B) = 0\] |
| Use when events cannot happen together. |
| 342 | Permutation formula | \[{}_nP_r=\frac{n!}{(n-r)!}\] |
| Count ordered selections. |
| 343 | Combination formula | \[{}_nC_r=\frac{n!}{r!(n-r)!}\] |
| Count unordered selections. |
| 344 | Binomial probability formula | \[P(X=k)=\binom{n}{k}p^k(1-p)^{n-k}\] |
| Find exactly k successes in n independent trials. |
| 345 | Expected value formula | \[E(X)=\sum xP(x)\] |
| Find long-run average outcome. |
| 346 | Normal distribution formula | \[f(x)=1/(\sigma \sqrt{2pi}) e^(-((x-\mu)^{2})/(2sigma^{2}))\] |
| Use the normal probability density curve. |
22. Financial Mathematics (18 formulae)
| # | Formula name | Formula or rule | Variables / notation | Use |
|---|---|---|---|---|
| 347 | Simple interest formula | \[I=Prt\] |
| Calculate interest without compounding. |
| 348 | Compound interest formula | \[A=P\left(1+\frac{r}{n}\right)^{nt}\] |
| Calculate interest with periodic compounding. |
| 349 | Continuous compound interest formula | \[A=Pe^{rt}\] |
| Calculate continuously compounded growth. |
| 350 | Future value formula | \[FV=PV(1+r)^n\] |
| Find future value after n periods. |
| 351 | Present value formula | \[PV=\frac{FV}{(1+r)^n}\] |
| Discount a future value to today. |
| 352 | Loan payment formula | \[PMT=\frac{Pr(1+r)^n}{(1+r)^n-1}\] |
| Find fixed payment for an amortizing loan. |
| 353 | Mortgage payment formula | \[M=\frac{Pr(1+r)^n}{(1+r)^n-1}\] |
| Find a fixed mortgage principal-and-interest payment. |
| 354 | Amortization formula | \[balance = P(1+r)^{k} - PMT((1+r)^{k} - 1)/r\] |
| Estimate remaining loan balance after k payments. |
| 355 | Depreciation formula | \[\begin{gathered}\text{straight-line depreciation = (cost - salvage) / useful life}\end{gathered}\] |
| Spread asset cost evenly over time. |
| 356 | Markup formula | \[\text{markup}=\text{selling price}-\text{cost},\quad \text{markup \%}=\frac{\text{markup}}{\text{cost}}\times100\%\] |
| Measure price increase over cost. |
| 357 | Markdown formula | \[\text{markdown}=\text{original price}-\text{sale price},\quad \text{markdown \%}=\frac{\text{markdown}}{\text{original}}\times100\%\] |
| Measure price reduction from original price. |
| 358 | Discount formula | \[\begin{gathered}\text{sale price = original price(1 - discount rate)}\end{gathered}\] |
| Apply a percentage discount. |
| 359 | Sales tax formula | \[\begin{gathered}\text{total = price(1 + tax rate)}\end{gathered}\] |
| Add sales tax to a purchase. |
| 360 | Profit formula | \[\begin{gathered}\text{profit = revenue - cost}\end{gathered}\] |
| Measure gain after costs. |
| 361 | Loss formula | \[\begin{gathered}\text{loss = cost - revenue}\end{gathered}\] |
| Measure shortfall when cost exceeds revenue. |
| 362 | Commission formula | \[\text{commission}=\text{sales}\times\text{commission rate}\] |
| Calculate earnings from sales rate. |
| 363 | Break-even formula | \[\begin{gathered}\text{break-even units = fixed costs / (price - variable cost)}\end{gathered}\] |
| Find units needed to cover costs. |
| 364 | Inflation formula | \[\begin{gathered}\text{real value = nominal value / (1 + inflation rate)\^{}n}\end{gathered}\] |
| Adjust money for price-level change. |
23. Calculus Readiness / Precalculus (16 formulae)
| # | Formula name | Formula or rule | Variables / notation | Use |
|---|---|---|---|---|
| 365 | Limit notation formula | \[\lim(x \to a) f(x) = L\] |
| State the value approached by a function. |
| 366 | Average rate of change formula | \[(f(b) - f(a)) / (b - a)\] |
| Find slope of a secant line. |
| 367 | Instantaneous rate of change formula | \[f'(a) = \lim(h \to 0) (f(a+h) - f(a))/h\] |
| Define derivative at a point. |
| 368 | Difference quotient formula | \[(f(x+h) - f(x)) / h\] |
| Prepare for derivative calculations. |
| 369 | Secant line slope formula | \[m_secant = (f(b) - f(a)) / (b - a)\] |
| Find slope through two points on a curve. |
| 370 | Tangent line slope formula | \[m_tangent = f'(a)\] |
| Find slope of a curve at one point. |
| 371 | End behavior formulas | \[study f(x) as x \to \infty and x \to -\infty\] |
| Describe graph behavior far left and right. |
| 372 | Polynomial end behavior rule | \[\begin{gathered}\text{leading term a\_n x\^{}n controls end behavior}\end{gathered}\] |
| Predict polynomial tails. |
| 373 | Rational function asymptote formulas | \[\begin{gathered}\text{vertical: denominator = 0}\\\text{horizontal/slant: compare degrees}\end{gathered}\] |
| Analyze rational-function boundaries. |
| 374 | Horizontal asymptote formula | \[\begin{gathered}\text{deg top < deg bottom -> y=0}\\\text{equal degrees -> y=leading coefficient ratio}\end{gathered}\] |
| Find horizontal asymptotes. |
| 375 | Vertical asymptote formula | \[\begin{gathered}\text{set simplified denominator = 0}\end{gathered}\] |
| Find x-values where a rational function is unbounded. |
| 376 | Slant asymptote formula | \[\begin{gathered}\text{slant asymptote = polynomial quotient when deg top = deg bottom + 1}\end{gathered}\] |
| Find oblique asymptotes by division. |
| 377 | Rational function simplification formula | \[\begin{gathered}\text{factor numerator and denominator, then cancel common nonzero factors}\end{gathered}\] |
| Simplify rational expressions and identify holes. |
| 378 | Trigonometric graph formulas | \[y = A \sin(B(x - C)) + D; period = 2pi/|B|\] |
| Graph sine and cosine transformations. |
| 379 | Exponential graph formulas | \[y = ab^(x - h) + k\] |
| Graph exponential transformations. |
| 380 | Logarithmic graph formulas | \[y = a log_b(x - h) + k\] |
| Graph logarithmic transformations. |
24. Matrices & Vectors (18 formulae)
| # | Formula name | Formula or rule | Variables / notation | Use |
|---|---|---|---|---|
| 381 | Matrix addition formula | \[(A+B)_{ij}=A_{ij}+B_{ij}\] |
| Add matching entries of same-size matrices. |
| 382 | Matrix subtraction formula | \[(A - B)_ij = A_ij - B_ij\] |
| Subtract matching entries of same-size matrices. |
| 383 | Scalar multiplication formula | \[(cA)_ij = cA_ij\] |
| Multiply every matrix entry by a scalar. |
| 384 | Matrix multiplication formula | \[(AB)_{ij}=\sum_k A_{ik}B_{kj}\] |
| Multiply rows by columns. |
| 385 | Identity matrix formula | \[AI = IA = A\] |
| Use the matrix version of 1. |
| 386 | Zero matrix formula | \[A + 0 = A\] |
| Use the matrix version of 0. |
| 387 | Determinant of 2x2 matrix | \[\det\begin{bmatrix}a&b\\c&d\end{bmatrix}=ad-bc\] |
| Find determinant of a 2 by 2 matrix. |
| 388 | Determinant of 3x3 matrix | \[a(ei - fh) - b(di - fg) + c(dh - eg)\] |
| Find determinant of [[a,b,c],[d,e,f],[g,h,i]]. |
| 389 | Inverse of 2x2 matrix | \[A^{-1}=\frac{1}{ad-bc}\begin{bmatrix}d&-b\\-c&a\end{bmatrix}\] |
| Invert a 2 by 2 matrix when determinant is nonzero. |
| 390 | Matrix equation formula | \[Ax = b\] |
| Represent linear equations compactly. |
| 391 | Vector magnitude formula | \[||v|| = \sqrt{v1^{2} + v2^{2} + ... + vn^{2}}\] |
| Find vector length. |
| 392 | Vector addition formula | \[<a,b> + <c,d> = <a+c,b+d>\] |
| Add vectors component by component. |
| 393 | Vector subtraction formula | \[<a,b> - <c,d> = <a-c,b-d>\] |
| Subtract vectors component by component. |
| 394 | Scalar multiplication of vector formula | \[k<a,b> = <ka,kb>\] |
| Scale a vector. |
| 395 | Dot product formula | \[u \cdot v = \sum u_i v_i = ||u||||v||\cos \theta\] |
| Measure projection and angle relation. |
| 396 | Cross product formula | \[u\times v=\langle u_2v_3-u_3v_2,\ u_3v_1-u_1v_3,\ u_1v_2-u_2v_1\rangle\] |
| Find a 3D vector perpendicular to two vectors. |
| 397 | Unit vector formula | \[u_hat = u / ||u||\] |
| Convert a nonzero vector to length 1. |
| 398 | Direction angle formula | \[\theta = atan2(y, x)\] |
| Find vector direction from components. |
25. Logic, Sets & Discrete Math (15 formulae)
| # | Formula name | Formula or rule | Variables / notation | Use |
|---|---|---|---|---|
| 399 | Set union formula | \[A\cup B=\{x:x\in A\ \text{or}\ x\in B\}\] |
| Combine elements from either set. |
| 400 | Set intersection formula | \[A\cap B=\{x:x\in A\ \text{and}\ x\in B\}\] |
| Find shared elements. |
| 401 | Set complement formula | \[A'=\{x\in U:x\notin A\}\] |
| Find elements outside a set within universe U. |
| 402 | Difference of sets formula | \[A-B=\{x:x\in A\ \text{and}\ x\notin B\}\] |
| Remove B elements from A. |
| 403 | Cartesian product formula | \[A\times B=\{(a,b):a\in A,\ b\in B\}\] |
| Build ordered pairs from two sets. |
| 404 | Venn diagram formula | \[n(A \cup B) = n(A) + n(B) - n(A \cap B)\] |
| Count elements in overlapping sets. |
| 405 | Inclusion-exclusion principle | \[n(A \cup B \cup C) = n(A)+n(B)+n(C)-n(AB)-n(AC)-n(BC)+n(ABC)\] |
| Count overlapping groups without double-counting. |
| 406 | Truth table formulas | \[\begin{gathered}\text{not p, p and q, p or q, p -> q}\end{gathered}\] |
| Evaluate compound logical statements. |
| 407 | Conditional statement formula | \[p \to q is equivalent to not p or q\] |
| Represent "if p, then q." |
| 408 | Converse formula | \[q \to p\] |
| Reverse a conditional statement. |
| 409 | Inverse formula | \[not p \to not q\] |
| Negate both parts of a conditional. |
| 410 | Contrapositive formula | \[not q \to not p\] |
| Use a logically equivalent form of p -> q. |
| 411 | Direct proof structure | \[\begin{gathered}\text{assume p, use definitions/theorems, conclude q}\end{gathered}\] |
| Prove a conditional directly. |
| 412 | Indirect proof structure | \[\begin{gathered}\text{assume not q, derive contradiction, conclude q}\end{gathered}\] |
| Prove by contradiction or contrapositive reasoning. |
| 413 | Mathematical induction formula | \[\begin{gathered}\text{base case true}\\\text{if P(k) -> P(k+1), then P(n) true for n >= base}\end{gathered}\] |
| Prove statements over integers. |
26. Advanced K-12 / AP & IB Extension (27 formulae)
| # | Formula name | Formula or rule | Variables / notation | Use |
|---|---|---|---|---|
| 414 | Derivative definition formula | \[f'(x)=\lim_{h\to0}\frac{f(x+h)-f(x)}{h}\] |
| Define instantaneous rate of change. |
| 415 | Power rule | \[\frac{d}{dx}x^n=nx^{n-1}\] |
| Differentiate powers of x. |
| 416 | Product rule | \[(fg)'=f'g+fg'\] |
| Differentiate a product. |
| 417 | Quotient rule | \[\left(\frac{f}{g}\right)'=\frac{f'g-fg'}{g^2}\] |
| Differentiate a quotient. |
| 418 | Chain rule | \[\frac{d}{dx}f(g(x))=f'(g(x))g'(x)\] |
| Differentiate a composition. |
| 419 | Derivatives of trigonometric functions | \[d(\sin x)=\cos x; d(\cos x)=-\sin x; d(\tan x)=\sec^{2} x\] |
| Differentiate basic trig functions. |
| 420 | Derivatives of exponential functions | \[d(e^{x})=e^{x}; d(a^{x})=a^{x} \ln a\] |
| Differentiate exponential functions. |
| 421 | Derivatives of logarithmic functions | \[d(\ln x)=1/x; d(log_a x)=1/(x \ln a)\] |
| Differentiate logarithmic functions. |
| 422 | Implicit differentiation formula | \[dy/dx = -F_x/F_y for F(x,y)=0\] |
| Differentiate equations not solved for y. |
| 423 | Related rates formula | \[\begin{gathered}\text{differentiate the relation with respect to t}\end{gathered}\] |
| Connect changing quantities over time. |
| 424 | Optimization formula | \[\begin{gathered}\text{critical points solve f'(x)=0 or f'(x) undefined}\end{gathered}\] |
| Find maxima and minima under constraints. |
| 425 | Riemann sum formula | \[\sum f(x_i^*)\Delta x\] |
| Approximate area by rectangles. |
| 426 | Left Riemann sum formula | \[L_n = \sum from i=0 to n-1 f(a + i \Delta x)\Delta x\] |
| Approximate area using left endpoints. |
| 427 | Right Riemann sum formula | \[R_n = \sum from i=1 to n f(a + i \Delta x)\Delta x\] |
| Approximate area using right endpoints. |
| 428 | Midpoint Riemann sum formula | \[M_n = \sum from i=1 to n f((x_(i-1)+x_i)/2)\Delta x\] |
| Approximate area using midpoints. |
| 429 | Trapezoidal rule | \[T_n = (\Delta x/2)(f(x0) + 2f(x1) + ... + 2f(x_(n-1)) + f(xn))\] |
| Approximate area with trapezoids. |
| 430 | Definite integral formula | \[\int_a^b f(x)\,dx=F(b)-F(a)\] |
| Compute signed area using an antiderivative. |
| 431 | Indefinite integral formula | \[\int f(x) dx = F(x) + C\] |
| Find a family of antiderivatives. |
| 432 | Fundamental theorem of calculus | \[\frac{d}{dx}\int_a^x f(t)\,dt=f(x),\quad \int_a^b f(x)\,dx=F(b)-F(a)\] |
| Connect differentiation and integration. |
| 433 | Basic integration rules | \[\int x^n\,dx=\frac{x^{n+1}}{n+1}+C,\quad n\ne-1\] |
| Integrate basic powers. |
| 434 | Integration by substitution | \[u = g(x), du = g'(x)dx\] |
| Reverse the chain rule. |
| 435 | Area under a curve formula | \[A = \int_{a}^{b} f(x) dx, f(x) \ge 0\] |
| Find area between a curve and the x-axis. |
| 436 | Area between curves formula | \[A = \int_{a}^{b} (top - bottom) dx\] |
| Find area between two curves. |
| 437 | Volume by disk method | \[V = \pi \int_{a}^{b} R(x)^{2} dx\] |
| Find volume of revolution with no hole. |
| 438 | Volume by washer method | \[V = \pi \int_{a}^{b} (R(x)^{2} - r(x)^{2}) dx\] |
| Find volume of revolution with a hole. |
| 439 | Volume by shell method | \[V=2\pi\int_a^b \text{radius}\times\text{height}\,dx\] |
| Find volume of revolution using cylindrical shells. |
| 440 | Differential equation separation formula | \[\frac{dy}{dx}=g(x)h(y)\Longrightarrow \int\frac{dy}{h(y)}=\int g(x)\,dx+C\] |
| Solve separable first-order differential equations. |
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- 1.OpenStax - Algebra and Trigonometry 2e Index(Accessed May 2026)
- 2.OpenStax - Precalculus 2e Basic Functions and Identities(Accessed May 2026)
- 3.OpenStax - Calculus Volume 1, Fundamental Theorem of Calculus(Accessed May 2026)
- 4.Khan Academy - Perimeter & area(Accessed May 2026)