Free Math Formula Calculators & Reference | MathHelp.me

Pre-Algebra

Area & Perimeter

$$A = lw \quad P = 2(l+w)$$

Pythagorean Theorem

$$a^2 + b^2 = c^2$$

Volume & Surface Area

$$V = \pi r^2 h$$

Algebra

Distance & Midpoint

$$d = \sqrt{(x_2-x_1)^2 + (y_2-y_1)^2}$$

Exponent Rules

$$a^m \cdot a^n = a^{m+n}$$

Factoring Quadratics

$$ax^2 + bx + c = (px + q)(rx + s)$$

Logarithm Rules

$$\log_b(xy) = \log_b x + \log_b y$$

Quadratic Formula

$$x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$$

Slope Formula

$$m = \frac{y_2 - y_1}{x_2 - x_1}$$

Slope-Intercept Form

Trigonometric Functions

$$\sin\theta = \frac{\text{opp}}{\text{hyp}}$$

Calculus

Chain Rule

$$\frac{d}{dx}[f(g(x))] = f'(g(x)) \cdot g'(x)$$

Power, Product & Quotient Rules

$$\frac{d}{dx}\left[x^n\right] = nx^{n-1}$$

Finance

Break-Even Point

$$Q = \frac{FC}{P - VC}$$

Future Value of an Annuity

$$FV = PMT \cdot \frac{(1+r)^n - 1}{r}$$

Loan Payment

$$M = P \cdot \frac{r(1+r)^n}{(1+r)^n - 1}$$

Percent Change

$$\%\,\text{change} = \frac{\text{new} - \text{old}}{|\text{old}|} \times 100$$

Present & Future Value

$$FV = PV\,(1 + r)^t$$

Return on Investment (ROI)

$$ROI = \frac{\text{gain} - \text{cost}}{\text{cost}} \times 100$$

Rule of 72

$$t \approx \frac{72}{r}$$

Simple & Compound Interest

$$A = P\!\left(1 + \frac{r}{n}\right)^{nt}$$

Statistics

Mean, Median, Mode & Std Dev

$$\bar{x} = \frac{\sum x_i}{n}$$