Quadratic Equations — Formula Sheet

A quadratic equation in variable x is of the form ax² + bx + c = 0, where a ≠ 0.

Key idea

If (px + q)(rx + s) = 0, then either px + q = 0 or rx + s = 0.

The quadratic formula gives the roots of ANY quadratic equation ax² + bx + c = 0.

The formula is

x = [-b ± √(b² - 4ac)] / 2a

This method involves expressing the quadratic equation ax² + bx + c = 0 as a product of two linear factors: (mx + p)(nx + q) = 0.

For any quadratic equation ax² + bx + c = 0, the roots are given by: x = (-b ± √(b² - 4ac)) / 2a.