Question

If the range of the function f(x)=x/4 is {28, 30, 32, 34, 36}, what is its domain?

{112, 120, 128, 136, 144}

{118, 122, 124, 132, 145}

{110, 118, 122, 124, 137}

{111, 124, 128, 132, 146}

Answer 1

The correct option is 1.

Explanation:

The given function is

`f(x)=(x)/(4)`

It can be written as

`y=(x)/(4)`

`4y=x`

Here, x is the domain of the function and y is the range of the function.

The range of the function is {28, 30, 32, 34, 36}, so the elements of domain are

`x=4(28)=112`

`x=4(30)=120`

`x=4(32)=128`

`x=4(34)=136`

`x=4(36)=144`

The domain of the function is {112, 120, 128, 136, 144}.

Therefore option 1 is correct.

Answer 2

The range is the y-coordinate while the domain is the x-coordinate
y = x/4
x = 4y
domain = {4(28), 4(30), 4(32), 4(34), 4(36)}
= {112, 120, 128, 136, 144}