Question

Consider function f.
f(x) = square root of 7x – 21
Place the steps for finding f-1(x) in the correct order.

Answer 1

Answer:

• f⁻¹(x) = 1/7x² + 3

Step-by-step explanation:

Given

• f(x) = $\sqrt{7x-21}$

To find

• Inverse of f(x)

Solution

Change f(x) → x, and x → y, and solve for y:

• x = $\sqrt{7y -21}$
• x² = 7y - 21
• 7y = x² + 21
• y = 1/7x² + 3

y = f⁻¹(x)

• f⁻¹(x) = 1/7x² + 3