Question

Which function is the inverse of Rx) = 8x + 4?

Answer 1

Answer:

D

Step-by-step explanation:

let y = f(x) and rearrange making x the subject

y = 8x + 4 ( subtract 4 from both sides )

y - 4 = 8x ( divide both sides by 8 )

$\frac{y-4}{8}$ = x

Change y back into terms of x with x = $f^{-1}$ (x)

$f^{-1}$ (x) = $\frac{x-4}{8}$ → D

Answer 2

Answer:

$B.~f^{-1}(x)=\frac{x-4}{8}$

Step-by-step explanation:

To find the inverse of a function, swap the places of the x and y variables and solve for y again.

$x=8y+4\\x-4=8y\\\frac{x-4}{8}=y$