We are given f(x) = 5x
and we are to find inverse of f(x).
Step 1:
Replace f(x) by y.
So,
y = 5x
Step 2:
Isolate x
So,
x = y/5
Step 3:
Replace x by f'(y)
So,
f'(y) = y/5
Step 4:
Replace all occurrences of y by x.
So,
f'(x) = x/5
Therefore, the inverse of f(x) = 5x is f'(x) = x/5