Answer:
f^-1(x) = (x² + 21)/7
Step-by-step explanation:
Since f(x) = y = √(7x – 21), to find the inverse of f(x) we have to write x in terms of y in order to make x the dependent variable and y the independent variable. The steps involved are:
Step 1: square both sides of the equation, y = √(7x – 21). Doing that, we have:
y² = 7x – 21
Step 2: Add 21 to both sides of the resulting equation. Doing that, we have:
y² + 21 = 7x
Step 3: Divide both sides of the equation by 7. Doing that we have:
x = (y² + 21)/7
Step 4: Replace x with f^-1(x) and y with x. Doing that, we have:
f^-1(x) = (x² + 21)/7
