Question

If f(x + y) = f(x) × f(y) ∀ x, y and f(5) = 2, f '(0) = 3, then f '(5) is

(a) 0

(b) 1

(c) 6

(d) 2.

Answer 1

(c) : Given f(x + y) = f(x) f (y)