Answer
(a) $$g(x)=(1+x)^3 \qquad h(x)= \sin (x^2)$$
(b) $$g(x)=\sqrt{1-x} \qquad h(x)= \sqrt[3]{x}$$
Work Step by Step
(a) By considering the functions $$g(x)=(1+x)^3 \qquad h(x)= \sin (x^2)$$ we have $$f(x)=(g \circ h)(x)=g(h(x))=(1+ \sin (x^2))^3.$$
(b) By considering the functions $$g(x)=\sqrt{1-x} \qquad h(x)= \sqrt[3]{x}$$ we have $$f(x)=(g \circ h)(x)=g(h(x))=\sqrt{1-\sqrt[3]{x}}.$$
