Answer
(a) $$g(x)=\sqrt{x} \qquad h(x)=x+2$$
(b) $$g(x)=|x| \qquad h(x)=x^2-3x+5$$
Work Step by Step
(a) By considering the functions $$g(x)=\sqrt{x} \qquad h(x)=x+2$$ we have $$f(x)=(g \circ h)(x)=g(h(x))=\sqrt{x+2}.$$
(b) By considering the functions $$g(x)=|x| \qquad h(x)=x^2-3x+5$$ we have $$f(x)=(g \circ h)(x)=g(h(x))=|x^2-3x+5|.$$
