Question

Given the function f(x) = 2x, find the value of f−1(16)

Answer choices

A) f−1(16) = 4
B) f−1(16) = 8
C) f−1(16) = 32
D) f−1(16) = 65,536

Answer 1

f(x) = 2x
x = f(x) / 2

f-1(x) = x/2

so f-1(16) = 8

Its B

Answer 2

ANSWER


`{f}^( - 1) (16) = 8`
Step-by-step explanation


The given function is


`f(x) = 2x`

We need to determine the expression for

`{f}^( - 1) (x)`

So we first of all let,


`y = f(x)`

This implies that,


`y = 2x`


We interchange x and y to get,


`x = 2y`


We now make y the subject to obtain,


`(x)/(2) = y`

Or


`y = (x)/(2)`

This is the inverse function,



`{f}^( - 1) (x) = (x)/(2)`

This implies that,


`{f}^( - 1) (16) = (16)/(2)`



`{f}^( - 1) (16) = 8`


The correct answer is B.