Question

F(x)=3x^2-4x+8G(x)=2x-5 use the functions above to find the value of g(f(-2)) I don’t understand how to do this

Answer 1

Given,

`f(x)=3x^2-4x+8,\text{g(x)=2x-5}`

To find g(f(-2)). we first find the value of f(-2).

The value of f(-2) is,

`\begin{gathered} f(-2)=3(-2)^2-4(-2)+8 \\ \text{ =3(4)+8+8} \\ \text{ =12+8+8} \\ \text{ =28} \end{gathered}`

So now to find the value of g(f(-2)),

`g(f(-2))=g(28)`

So the value of g(28) is,

`\begin{gathered} g(28)=2(28)-5 \\ \text{ =56-5} \\ \text{ =51} \end{gathered}`

So the value of g(f(-2)) is 51.