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
