Essential equations to know for the ACT?

I'm preparing for the ACT and I want to make sure I've got all the essential equations locked down. Like, what math equations/formulas should I absolutely know, and which sections do they apply to? It would be great if somebody could give me a quick rundown. Thanks!

Preparing for the ACT math section is all about having a strong foundation in various mathematical topics. To make sure you're well-equipped for the test, here's a list of some essential equations and formulas you should know:

1. Arithmetic and Number Concepts

- Percentages: Percent = (Part/Whole) x 100

- Ratios: a:b, where "a" and "b" are the quantities being compared

2. Algebra

- Pythagorean Theorem: a^2 + b^2 = c^2, where a and b are the legs of a right triangle and c is the hypotenuse

- Quadratic Formula: x = (-b ± √(b^2 - 4ac))/(2a), where ax^2 + bx + c = 0

- Slope-Intercept Form: y = mx + b, where m is the slope and b is the y-intercept of a linear equation

- Point-Slope Formula: y - y1 = m(x - x1), where m is the slope, and (x1, y1) is a point on the line

3. Geometry

- Area of a triangle: A = (1/2)bh, where b is the base and h is the height

- Area of a rectangle: A = lw, where l is the length and w is the width

- Area of a circle: A = πr^2, where r is the radius

- Circumference of a circle: C = 2πr, where r is the radius

- Volume of a rectangular prism: V = lwh, where l is the length, w is the width, and h is the height

4. Trigonometry

- SOHCAHTOA: Basic trigonometric functions

Sine = Opposite/Hypotenuse,

Cosine = Adjacent/Hypotenuse,

Tangent = Opposite/Adjacent

Remember to practice using these equations and formulas, as well as reviewing additional math concepts and strategies leading up to the test. Good luck with your ACT preparation!