Answer:
True.
Explanation:
For example let f(x) = 3x + 1 then f-1(x) is found as follows
Let f(x) = y = 3x + 1 then
3x = y - 1
x = (y-1) / 3
x = f-1(x) = (x - 1)/3.
So:
Replacing the x in y by (x - 1)/3 :-
x = f(-1)(y) = ( (3x + 1) - 1) / 3
= 3x / 3
= x.
So y = f(x).