4.6 The Quadratic Formula

How can we solve the equation 0 = x² - x - 4?

Ex 1 Solve 0 = x² - x - 4

The process we can use to solve any quadratic is complete the square, then isolate x. This process can be long, therefore it is time to develop the quadratic formula, which uses the most general possible quadratic.

Solve: 0 = ax² + bx + c

Ex 2 Solve 0 = 2x² - 5x - 1

p. 129# 3-6odd, 10-12odd