Question

Find the values of p and q for which 3/2 and -3 are two roots of the quadratic equation px^2+qx-9=0 in detail explanation

Answer 1

Answer:

x=3/2

px²+qx-9=0

p(3/2)²+q(3/2)-9=0

9p/4+3q/2-9=0

9p+6q-36=0 -(i)

x=-3

px²+qx-9=0

p(-3)²+q(-3)-9=0

9p-3q-9=0 -(ii)

Subtracting eq (i) and (ii)

9p+6q-36-(9p-3q-9) =0

9p+6q-36-9p+3q+9 =0

9q-27=0

9q=27

q=3

Putting value of q in eq (i)

9p+6q-36=0

9p+6(3)-36=0

9p+18-36=0

9p-18=0

9p=18

p=2