Question

If f(x) = x2 and g(x) = 3x - 1, find f(g(x))

Answer 1

Given the following functions:

$\begin{gathered} f(x)=x^2 \\ g(x)=3x-1 \end{gathered}$

To compose then, is basically use the inside function as the argument.

$f(g(x))=f(3x-1)$

If we call '3x-1' as 'u'

We know the following

$\begin{gathered} f(u)=u^2 \\ u=3x-1\Rightarrow f(3x-1)=(3x-1)^2 \end{gathered}$

And this is our answer.

$f(x)=(3x-1)^2$