BELL-WORK Solve TB pg 545 # 20 by graphing

Reminders MICA Assignment

HW 3.1 HW with corrections due Wednesday!

HW 3.1(b) Solutions 1.(1,-3); minimum 2.(3,-1); minimum 3.(1,5); maximum 5.(0,3); x = 0 6.(2,5); x = 2 7.(-¼,-14⅛); x = -¼

Quiz 3.1 Review Signatures?

Guiding question: How are quadratic equations solved?

Solving Quadratic Equations Quadratics can be solved by factoring quadratic formula & graphing.

Solving Quadratics by Graphing Solve y = 2x 2 + 4x – 100 by graphing. Notice that the x-intercepts are not clear. Pres 2 nd CALC Select ‘zero’ Give a left bound Give a right bound Give a guess

Solving Quadratics by Graphing Yesterday we learned that a quadratic can have no solution, 1 solution or 2 solutions. Before we solve a quadratic equation we can tell how many solutions it will have by calculating the discriminant. The discriminant tells how many solutions a quadratic equation has.

The Discriminant of a Quadratic The discriminant of a quadratic is the result of B 2 – 4AC Where have you seen the discriminant? If B 2 – 4AC > 0, there are two solutions If B 2 – 4AC = 0, there is one solution If B 2 – 4AC < 0, there are no solutions

The Discriminant of a Quadratic Find the number of solutions of x 2 = -3x – 7. A = 1 B = 3 C = 7 B 2 – 4AC = 9 – 417 = 9 – 28 < 0 There will be no solution. TB pg 571 # 3 TB pg 572 # 32,34

Real-World Quadratics TB pg 572 # 22 When the ball hits the ground, its height will be... 0 So substitute y with 0! 0 = x 2 + x By the quadratic formula, x = -2.5 or Since distance cannot be negative, ft. PW 9-6 # 16,42

Who wants to answer the Guiding question? How are quadratic equations solved?