Vital ACT formulas?

Hey folks, what are the most essential math formulas I absolutely need to memorize for the ACT? I don't want to miss out on easy points because I didn't memorize a formula.

While the ACT does provide some of the most common formulas on the test itself, there are still quite a few that you'll want to have memorized for the Math section. Here's a list of vital ACT math formulas that would be beneficial to remember:

Algebra and Functions:

1. Slope of a line: m = (y2-y1) / (x2-x1)

2. Equation of a line: y = mx + b (m = slope, b = y-intercept)

3. Midpoint: (x1 + x2)/2, (y1 + y2)/2

4. Distance: square root of [(x2 - x1)^2 + (y2 - y1)^2]

Geometry:

1. Area of a triangle: 1/2 base x height

2. Area of a rectangle: length x width

3. Area of a circle: πr^2 (r = radius)

4. Circumference of a circle: 2πr

5. Pythagorean theorem: a^2 + b^2 = c^2 (used for right triangles)

Trigonometry:

1. Sine, cosine, and tangent values (basic ratios regarding right triangles). The ratios are:

- Sine = Opposite/Hypotenuse

- Cosine = Adjacent/Hypotenuse

- Tangent = Opposite/Adjacent

2. The sine and cosine of 30, 45, and 60 degrees

Probability and Statistics:

1. Average/mean: sum of all numbers/number of numbers

2. Probability: number of desired outcomes/number of total outcomes

3. Percentages: part = (percent/100) x whole

Remember, though, that understanding the concepts behind these formulas is just as important. Rote memorization won't help if you don't know when or how to apply these formulas. Good luck with your test prep!