1. SWBAT… solve quadratic equations Tues, 2/7 Agenda 1. Warm-up (15 min) 2. Solving quadratic equations (10 min) 3. Graphing calculator activity (10 min) 4. 4 additional problems (10 min) Warm-Up: Factor each expression: 1. x 2 + 11x + 18 2. p 2 – 10pq + 16q 2 3. n 6 + n 3 – 56 HW#6: Quadratic Equations: x 2 + bx + c

2. Steps to solve quadratic equations: 1.) Set equation = 0 2.) Factor the equation 3.) Set each factor = 0 4.) Solve each variable 5.) Check both solutions Example: x 2 + 11x = -18 1.) x 2 + 11x + 18 = 0 2.) (x + 2)(x + 9) = 0 3.) x + 2 = 0 or x + 9 = 0 4.) x = -2 or x = -9

3. CHECK: Plug both answers into original equation x 2 + 11x = -18 or x 2 + 11x = -18 (-2) 2 + 11(-2) = -18 (-9) 2 + 11(-9) = -18 4 – 22 = -18 81 – 99 = -18 -18 = -18 -18 = -18

4. On your graphing calculator graph x 2 + 11x + 18 You will need to change the “window”  x-min = -15  y-max = 15  y-min = -15  y-max = 15 What conclusion can you make about the solutions of a quadratic and it’s graph?  The solutions of a quadratic equation is where the parabola crosses the x-axis. The solutions of a quadratic may also be called roots, zeros or x-intercepts.

5. Solve each equation: 1. -42 + m 2 – m = 0 2. c 2 = 3c 3. Find all the values of k: x 2 + kx – 19 4. A rectangle has an area represented by x 2 – 4x – 12 feet 2. If the length is x + 2 feet, what is the width of the rectangle?