1. Using the Quadratic Formula to Find the Roots y = 3x 2 – 6x – 20 The roots are the x values when y = 0 xy -325 -24 -1-11 0-20 1-23 2-20 3-114 525 From the table you can see that the y values change sign between –2 and –1 and between 3 and 4 So the roots lie between –2 and –1 and between 3 and 4 Use your calculator to make a table of values using y = 3x 2 – 6x – 20 and the TABLE key

2. Using the Quadratic Formula to Find the Roots y = 3x 2 – 6x – 20 The roots are the x values when y = 0 a = 3b = –6c = –20 The Quadratic formula is used to find the roots You can check this using x intercept on the CALC menu

3. Using the Quadratic Formula to Find the Roots y = 2x 2 + 3x – 12 The roots are the x values when y = 0 2x 2 + 3x – 12 a = 2b = 3c = –12 The Quadratic formula is used to find the roots You can check this using x intercept on the CALC menu