Processing math: 100%
Home / Aptitude Tests / Further Mathematics / Given that \(f(x) = ...
Given that f(x)=x+12, find f1(2)....

Given that f(x)=x+12, find f1(2).

A.

-5

B.

-3

C.

12

D.

5

Correct answer is A

Let f(x)=y, then we have

y=x+122y=x+1;x=2y1

Let f1(x)=x;x=2y1, replacing y with x,

f1(x)=2x1f1(2)=2(2)1=5