The sum and the product of Roots of Quadratic Equations.pptx

mathematics 9

1. The Sum and the Product of Roots of Quadratic Equations

2. Activity 1: let’s do Addition and Multiplication! 1. 7 + 15 = 2. -9 + 14 3. -6 + (-17) 4.(   5. (-6) (-2) = Perform the indicated operation then answer the questions that follow. 6.(  

3. Activity 2: Find my roots! 1. x 2 + 3x + 2 = 0 2. s 2 - 5s + 6 = 0 3. r 2 + 2r -8 = 0 4. 4x 2 +16x + 15 = 0 5. 3m 2 - 8m - 4 = 0 Find the roots of each of the following quadratic equations using any method. Answer the questions that follow.

4. QuQ Remember that the roots of a quadratic equation can be determined using the quadratic formula x = .  

5. QuQ From the quadratic formula let x 1 = and x 2 = be the roots. Let us now find the sum and the product of these roots.  

6. QuQ Sum of the Roots of Quadratic Equation x 1 + x 2 = +   x 1 + x 2 =   x 1 + x 2 =   x 1 + x 2 =   The sum of the roots of quadratic equation is  

7. QuQ Product of the Roots of Quadratic Equation x 1 x 2 = (   x 1 x 2 =   x 1 x 2 =   The product of the roots of quadratic equation is   x 1 x 2 =   x 1 x 2 =  

8. QuQ Example 1: Find the sum and product of the roots of 2x 2 + 8x - 10 = 0

9. QuQ The values of a, b, and c in the equation are 2, 8, and -10, respectively. Solution

10. QuQ The Sum of the roots =   Solution The Sum of the roots =   The sum of the roots of 2x 2 + 8x -10 is -4 .

11. QuQ Product of the roots =   Solution Product of the roots =   The product of the roots of 2x 2 + 8x -10 is -5 .

12. QuQ Example 2. Use the values of a, b, and c in finding the roots of the quadratic equation x 2 + 7x - 18 = 0

13. QuQ The values of a, b, and c in the equation are 1, 7, and -18, respectively. Solution

14. QuQ The sum of the roots =   Solution The Sum of the roots =   The sum of the roots of x 2 + 7x -18 is -7 .

15. QuQ Product of the roots =   Solution product of the roots =   The product of the roots of x 2 + 7x -18 is -18 .

16. QuQ Activity 3. This is my Sum and this is my Product. Who am I? 1.   2.   3.   4.   5.  

17. QuQ Activity 3. This is my Sum and this is my Product. Who am I? 6.   7.   8.   9.   10.