Exercise 3.9: Quadratic Equations

Exercise 3.9

1. Determine the quadratic equations, whose sum and product of roots are

(i) -9, 20

 (ii) 5/3, 4

(iii) -3/2, -1

(iv) −(2 −a )2 , (a + 5)2

2. Find the sum and product of the roots for each of the following quadratic equations

(i) x 2 + 3x − 28 = 0

(ii) x 2 + 3x = 0

(iii) 3 + 1/a = 10/ a2

(iv) 3y 2 − y − 4 = 0

Answers:

1. (i) x 2 + 9x + 20 = 0 (ii) 3x 2 − 5x + 12 = 0 (iii) 2x 2+ 3x − 2 = 0 (iv) x2 + (2-a2)x+(a+5)2  = 0

2.(i) -3 , -28  (ii) -3 , 0 (iii) –1/3, -10 /3 (iv) 1/3, -4/3