Question

The roots of f(x) = 0 are 1 and -2. What are the roots of f(2x)=0?

1 and -2

1/2 and -1

-1/2 and 1

2 and -4

-2 and 4

Answer 1

@ranga

Answer 2

Roots of f(x) are 1 and -2 suggests that f(x) =a(x-1)(x+2)
f(2x) = a(2x-1)(2x+2). Its roots are when a(2x-1)(2x+2) = 0 which happens when:
x = 1/2 and x = -1.