Question

If f(x) = -4x + 2 and g(x) = sq root X – 8,
what is (fºg)(12)?​

Answer 1

`(fog)(12)=-6`

Explanation:

Recall that the notation:
`(fog)(12)` is the same as:
`f(g(12))` which means the value of the function f when you give it as input the value obtained by evaluating g(12).

Therefore, we need to start finding what g(12) is using the definition :

`g(x)=√(x-8)` and evaluating it as x = 12.

`g(x)=√(x-8)\\g(12)=√(12-8)\\g(12)=√(4)\\g(12)=2`

So now we use this answer "2" as input for f(x):

`f(x)=-4x+2\\f(2)=-4(2)+2\\f(2)=-8+2\\f(2)=-6`

Therefore,
`(fog)(12)=-6`