1.4 Quadratic Equations
General Form of a Quadratic Equation A quadratic equation is also known as a second-degree polynomial equation
Methods for Solving Factoring Extracting the Square Roots Completing the Square Quadratic Formula
Method #1 - Factoring Use the Zero-Factor Property If ab=0, then a=0 or b=0. **Remember** You can only use the Zero-Factor Property for an equation written in general form! First step has to be to set the equation equal to zero
Solve By Factoring
Extracting the Square Root
Solve by Extracting the Square Root
Method #2 – Completing the Square Extracting the Square Root is rather simple, but what if we had been given the last example in general form… Is it as easy? Well we can make it that easy by completing the square!
Completing the Square
Solve by Completing the Square
Complete the Square for the following… Notice anything???
Method #4 Quadratic Formula
Number of Solutions can be determined by the DISCRIMINANT If D>0 (positive), then the quadratic equation has 2 distinct real solutions and 2 x intercepts. If D=0, then the quadratic equation has one repeated real solution and its graph has 1 x intercept. If D<0 (negative), then the quadratic equation has no real solutions and its graph has no x intercepts.
Use the Quadratic Formula to Solve
Try a Word Problem A bedroom is 3 feet longer than it is wide and has an area of 154 square feet. Find the dimensions of the room.