What are some essential formulas to remember for the ACT?

Hey everyone, I'm prepping for the ACT and wondering if there are any key formulas I should definitely memorize? Any help would be appreciated!

Of course! The ACT Math section covers a wide range of topics, so knowing some of the essential formulas can save you time and help you answer the questions more efficiently. Here's a list of important formulas to remember:

1. Quadratic Equation: Given a quadratic equation in the form ax^2 + bx + c = 0, the solution can be found using the quadratic formula:

x = (-b ± √(b^2 - 4ac)) / 2a

2. Slope: Given two points (x1, y1) and (x2, y2), the slope of the line connecting the points is:

m = (y2 - y1) / (x2 - x1)

3. Slope-Intercept Form: The equation of a line with slope m and y-intercept b is given by:

y = mx + b

4. Point-Slope Form: The equation of a line with slope m and passing through a point (x1, y1) is given by:

y - y1 = m(x - x1)

5. Distance Formula: Given two points (x1, y1) and (x2, y2), the distance between them is:

d = √((x2 - x1)^2 + (y2 - y1)^2)

6. Midpoint: Given two points (x1, y1) and (x2, y2), the midpoint is:

M = ((x1 + x2) / 2, (y1 + y2) / 2)

7. Area of a Triangle: Given a triangle with base b and height h, the area is:

A = (1/2)bh

8. Pythagorean Theorem: In a right triangle with legs of length a and b and hypotenuse of length c:

a^2 + b^2 = c^2

9. Trigonometric Ratios: In a right triangle with an angle θ, opposite side length o, adjacent side length a, and hypotenuse length h:

sin(θ) = o / h

cos(θ) = a / h

tan(θ) = o / a

These ratios are often remembered using the phrase SOH CAH TOA.

10. Circle Circumference: Given a circle with radius r:

C = 2πr

11. Circle Area: Given a circle with radius r:

A = πr^2

12. Volume of Rectangular Prisms: Given a rectangular prism with length l, width w, and height h:

V = lwh

13. Volume of Cylinders: Given a cylinder with radius r and height h:

V = πr^2h

Remember to practice using these formulas to become more comfortable applying them during the test. Good luck with your ACT preparation!