If $f(x)=2x-5$ and $g(x)=x^2+1$ , what is g(f(x))?

Question

43383 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2017-01-05T09:57:29

The answer is $=4x^2-20x+26$

This is a composition of functions

$f(x)=2x-5$

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

$g(f(x))=g(2x-5)=(2x-5)^2+1$

$=4x^2-20x+25+1=4x^2-20x+26$

$f(g(x))=f(x^2+1)=2(x^2+1)-5$

$=2x^2+2-5=2x^2-3$

$g(f(x))!=f(g(x))$

If f(x)=2x-5f(x)=2x-5 and g(x)=x^2+1g(x)=x^2+1, what is g(f(x))?