Question

Determine the domain of the function f (x) = 2x - 4 when the range is (0, 12, 20)

Answer 1

The domain is (2,8,12)

Explanation:

we have

`f(x)=2x-4`

we know that

The range is (0,12,20)

Find the domain

1) For f(x)=0 -----> Find the value of x

substitute the value of f(x) in the equation and solve for x

`0=2x-4`

`2x=4`

`x=2`

therefore

For f(x)=0 the domain is x=2

2) For f(x)=12 -----> Find the value of x

substitute the value of f(x) in the equation and solve for x

`12=2x-4`

`2x=12+4`

`x=8`

therefore

For f(x)=12 the domain is x=8

3) For f(x)=20 -----> Find the value of x

substitute the value of f(x) in the equation and solve for x

`20=2x-4`

`2x=20+4`

`x=12`

therefore

For f(x)=20 the domain is x=12

therefore

The domain is (2,8,12)