How do you find the compositions given f(x) = |x - 2f(x)=x2|, g(x) = sqrtxg(x)=x?

1 Answer
Jul 5, 2018

f(g(x))=f(sqrt(x))=|sqrt(x)-2|f(g(x))=f(x)=x2 and g(f(x))=g(|x-2|)=sqrt(|x-2|)g(f(x))=g(|x2|)=|x2|

Explanation:

Every function has an input and an output. Composing two functions means to use the output of the first as the input for the second.

So, f(x)f(x) takes an input xx and outputs the absolute value of the input minus two.
g(x)g(x) takes an input xx and ouputs the square root of the input.

So, f(g(x))=f(sqrt(x))=|sqrt(x)-2|f(g(x))=f(x)=x2 and g(f(x))=g(|x-2|)=sqrt(|x-2|)g(f(x))=g(|x2|)=|x2|