Step-by-step explanation:
Given
f(x) = 1/3x + 13
f^-1(x) = ?
Now
Let y = f(x)
or y = 1/3x + 13
Interchanging the role of x and y
x = 1/3y + 13
x - 13 = 1/3y
y = x - 13
3
Therefore f^-1(x) = x - 13
Hope it will help you.
