ACT Math: Core Concepts

What is the formula for the slope (m) of a line passing through the points (x1, y1) and (x2, y2)?

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

What is the formula for the area of a circle with radius r?

Area = πr²

In a right triangle with legs a and b and hypotenuse c, what is the Pythagorean theorem?

a² + b² = c²

How do you calculate the arithmetic mean of a set of numbers?

Divide the sum of all the numbers by the total count of numbers in the set.

What does the acronym FOIL stand for when multiplying two binomials?

First, Outer, Inner, Last

In trigonometry (SOH-CAH-TOA), what is the ratio for the sine of an angle?

Sine = Opposite / Hypotenuse

What is the formula for the midpoint between two points (x1, y1) and (x2, y2)?

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

What is the quadratic formula used to solve ax² + bx + c = 0?

x = [-b ± √(b² - 4ac)] / 2a

What is the standard form equation of a circle with center (h, k) and radius r?

(x - h)² + (y - k)² = r²

What is the distance formula between two points (x1, y1) and (x2, y2)?

d = √[(x2 - x1)² + (y2 - y1)²]