Numbers

Let f(x) = x2 and g(x) = 2x, for all real x. Then the value of f(f(g(x)) + g(f(x))) at x = 1 is

  1. 16
  2. 18
  3. 36
  4. 40

Answer

f[f(2x) + g(x2)]

As x = 1,

f[f(2) + g(1)]

= f[22 + 2(1)]

= f[6]

= 62

= 36

The correct option is C.