Question

If 1 is a root of the quadratic equation 3x^2+ax-2=0 and the quadratic equation a(x^2+bx )-b=0 has equal roots find b

Answer 1

putting x=1

3+a-2=0

a=2-3

a=-1

putting a=1 in the 2nd equ.

-1(1^2+b×1)-b=0

-(1+b)-b=0

-1-b-b=0

-1-2b=0

-1=2b

b=-1/2.

hence, b=-1/2.