Question

What is the inverse of the function f(x) = x +3?

Answer 1

1- First, replace f(x) with y

f(x) = x +3  ⇒ y = x + 3

2. Replace every x with a y and replace every y with an x .

y = x + 3 ⇒ x = y + 3

3. Solve the equation from Step 2 for y.

x = y + 3  ⇒ y = x-3

4 - Replace y with f⁻¹(x).

f⁻¹(x) = x-3

The inverse is f⁻¹(x) = x-3