9.3 Solving Quadratic Equations by the Quadratic Formula
Solving Quadratic Equation by Completing the Square
Solving Quadratic Equation by Completing the Square
Your Turn This is (x + 2) 2. Form perfect trinomial squares by adding an appropriate term. x 2 + 4x x 2 – 6x x 2 – 5x This is (x – 3) 2.
Solve by Completing the Square
Example Solve by completing the square: 4x 2 –3 = –4x Solution: 4x 2 –3 = –4x 4x 2 + 4x – 3 = 0
Example – Solution We then use completing the square to solve the equation. cont’d or
Quadratic Formula
Derivation of the Quadratic Formula
Derivation of the Quadratic Formula
Derivation of the Quadratic Formula
Derivation of the Quadratic Formula
Example
Your Turn
Determine if a quadratic equation has real- number solutions
A TV screen is 46-inch wide. The 46-inch screen is measured along the diagonal. The screen is rectangular in shape and is 17 inches wider than is is high. Find the dimensions of a screen. Solution: 1.Let h = height Then, w = h Equation: h 2 + (h + 17) 2 = 46 2 Application