Essential ACT formulas?

Hey everyone! I'm prepping for the ACT this year, and I'm wondering if there's a list of essential formulas I should memorize for the math section. Anyone have any advice on this? Thanks in advance!

Hey there! Good luck with your ACT preparation! Here's a list of essential formulas to memorize for the ACT math section. While not every formula may be applicable to every question, having these memorized will definitely help you tackle a variety of problems more efficiently.

1. Arithmetic & Algebra:

- Basic operations (+, -, ÷, ×)

- Powers and roots (x^2, x^3, √x)

- Order of operations (PEMDAS)

- Distributive property (a(b+c) = ab + ac)

- Factoring (including difference of squares, i.e., a^2-b^2 = (a+b)(a-b))

- Linear equations (y = mx + b)

- Quadratic formula (x = [-b ± √(b^2 - 4ac)] / 2a)

2. Geometry & Trigonometry:

- Perimeter and area of common shapes (rectangle, triangle, circle, trapezoid, parallelogram)

- Pythagorean theorem (a^2 + b^2 = c^2)

- Circle properties (e.g., diameter, radius, circumference, π = 3.14)

- Triangle properties (isosceles, equilateral, right)

- SOHCAHTOA (sine, cosine, tangent of right triangles)

- Angle relationships (complementary, supplementary, and vertical angles)

- Volume of solids (cylinder, cone, sphere, pyramid)

3. Probability & Statistics:

- Probability (P(event) = (number of successful outcomes) / (number of possible outcomes))

- Basic probability rules (e.g., P(A and B) and P(A or B), probabilities add up to 1)

- Mean (average) formula (sum of all items / number of items)

- Median (middle value)

- Mode (most frequent value)

- Range (maximum value - minimum value)

4. Miscellaneous:

- Complex numbers (real and imaginary components; i^2 = -1)

- Logarithm properties (e.g., logb(xy) = logb(x) + logb(y), logb(x^y) = ylogb(x))

- Percent change (final value - initial value / initial value x 100%)

This list should give you a good starting point for your preparation. Make sure to practice different types of problems to help you become familiar with applying these formulas in various contexts. Good luck with your studying, and I hope you do well on the ACT!