100 likes | 246 Views
9.7 Using the Quadratic Formula. Objective: SWBAT use the quadratic formula to find the roots of a second-degree polynomial and to solve quadratic equations. Mini Quiz 28. 1. Find the missing number for x 2 – 18 x + ___ 2. Solve x 2 –3 x + 4 = 8 3. Solve x 2 – 8 x = 7.
E N D
9.7 Using the Quadratic Formula Objective: SWBAT use the quadratic formula to find the roots of a second-degree polynomial and to solve quadratic equations.
Mini Quiz 28 1. Find the missing number for x2 – 18x + ___ 2. Solve x2 –3x + 4 = 8 3. Solve x2 – 8x = 7
Overview Methods in Solving Quadratic Equations: Graphing Square Roots Factoring ( )( ) = 0 Completing the Square ( )2 Quadratic Formula
Quadratic Formula What are we finding? x-intercepts Vertex and Axis of Symmetry y-intercept x = 0
The Song! Opposite of b Plus or Minus Root b square minus 4 a c all over 2 a
The Story! The negativeboy, couldn’t decide whether or not to go to the radical party. He didn’t want to be square, so he missed out on 4awesome cuties, and it was all over at 2am
Quadratic vs. QuadraticFunction Equation y = ax2 + bx + c ax2 + bx + c = 0 Finds x-intercepts Solves the equation of the graph (x = ?) Standard Form Quadratic Formula
Calculate Find the x-intercepts or solutions. 1. x2 – 2x = -1 2. y = -2x2 – 4x 3. y = 2x2 – 5x + 4 4. -x2 = -5x – 2 x = 1 x = -2, x = 0 No solution
Calculate Find the x-intercepts or solutions. 5. x2 – 2x – 3 = 0 6. y = x2 – 5x + 3 7. x2 + 6 = 5x 8. -2x2 = 4x – 7 x = -1, x = 3 x = 2, x = 3
Wrap Up Quadratic Formula can be used to solve any quadratic equation! HW: P. 466 #1, 3, 10, 13, 15, 25-31 odd, 47-53 odd DLUQ: How does the Quadratic Formula tell you there’s “no solution”?