Question

2. If f(x) = 3x - 5 and g(x) = x2, find (fog)(3)
20
27
22
18

Answer 1

Composite Functions

We can solve with composite functions just as we do variables, by substituting one function into the other.

Solving the Question

`f(x) = 3x - 5`

`g(x) = x^2`

First, find
`f\circ g(x)` by substituting g(x) into f(x):

`f(x) = 3x - 5\\f\circ g(x)=3(x^2)-5\\f\circ g(x)=3x^2-5`

Now, find
`f\circ g(3)`:

`f\circ g(3)=3(3)^2-5\\f\circ g(3)=3(9)-5\\f\circ g(3)=27-5\\f\circ g(3)=22`

Answer

22