Question

Find the inverse of the function: f ( x ) = 1 5 x + 4 Group of answer choices f − 1 ( x ) = 4 x − 5 f − 1 ( x ) = − 5 x − 4 f − 1 ( x ) = x − 4

Answer 1

D

Explanation:

Answer 2

D

Explanation:

So we have the function:

`f(x)=(1)/(5)x+4`

To find the inverse, simply switch x and f(x), change f(x) to f⁻¹(x), and solve for it. Thus:

`x=(1)/(5)f^(-1)(x)+4`

Subtract 4 from both sides:

`x-4=(1)/(5)f^(-1)(x)`

Multiply both sides by 5:

`f^(-1)(x)=5x-20`

So that's our inverse :)

So, our answer is D