CAT Functions

Question

Qn. f(x + y) = f(x)f(y) for all x, y, f(4) = +3 what is f(-8)?

A.      1/3

B.      1/9

C.      9

D.      6

Answer Choice: B

Explanatory Answer

f(x + 0) = f(x) f(0)

f(0) = 1

f(4 + -4) = f(0)

f(4 + -4) = f(4) f(-4)

1 = +3 x f(-4)

f(-4) = 1/3

f(-8) = f(-4 + (-4)) = f(-4) f(-4)

f(-8) = 1/3 x 1/3 = 1/9 

Answer Choice (B)