If $f(x)=3x+4$ and $g(x)=x^2-1$ , how do you find $f(g(x))$ ?

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Answer 1 · 2017-01-21T17:01:08

$f(g(x))=3x^2+1$

Substitute x=g(x) that is $x=x^2-1$ into f(x).

$rArrf(g(x))=f(color(red)(x^2-1))$

$=3(color(red)(x^2-1))+4$

$=3x^2-3+4=3x^2+1$

If f(x)=3x+4f(x)=3x+4 and g(x)=x^2-1g(x)=x^2-1, how do you find f(g(x))f(g(x))?