6.3 Finding the Roots The roots of a quadratic function are the places that a parabola crosses the x axis. roots Not all parabolas have 2 roots. Sometimes they have 1 root or no roots. 1 root No roots (parabola never touched x axis) Hint: Roots can also be called Zeros or x intercepts X axis

6.3 Finding the Roots We are going to use the Diamond Method to find our roots. You mastered Diamond Method in MT4 and practiced it again in MT5. Now let’s use our roots to graph. Please find the roots of the equation x 2 + 6x – 16 = 0 and graph… Answer: x 2 + 6x – 16 = 0 – (x + 8)(x – 2) = 0 Now for the roots… (x + 8) = 0 (x – 2) = 0 X=-8, 2

6.3 Finding the Roots The last thing to do is to plot your points on a graph… X=-8, 2 That’s all. If you prepared yourself with MT5, this should be easy! X axis Let’s try one more example without the steps…

6.3 Finding the Roots X=-7, 4 X axis Let’s try one more example without the steps… f (x) = - (x 2 + 4x – 21) = 0 Notice the “-” in front of the equation. This will make your parabola “sad”. ( )( ) = 0 – x + 7 x – 4 The parabola is sad because the “x 2 ” is negative!