Question

If F(x)=3x-4 and g(x)=9x^2-16, find fog(1)

Answer 1

fog(x) = -25

Step-by-step explanation:
`\begin{gathered} \text{Given: } \\ f(x)\text{ = 3x - 4} \\ g(x)\text{ = }9x^2-16 \\ \\ We\text{ n}eed\text{ to find fog(1)} \end{gathered}`

First we need to find fog(x):

We would replace the value of x in f(x) with the function g(x):

`\begin{gathered} fog(x)=3(9x^2\text{ }-16)-4 \\ fog(x)=27x^2\text{ - 48 - 4} \\ fog(x)=27x^2\text{ - 52} \end{gathered}`

Next we will replace the value of x with 1 in function fog(x):

`\begin{gathered} fog(1)=27(1)^2\text{ - 52} \\ fog(x)=\text{ 27 - 52} \\ fog(x)=\text{ }-25 \end{gathered}`