Answer
(a). $-x $, $[-2,\infty)$, $(-\infty, 2]$
(b). $\sqrt {4-x^2}$, $[-2,2]$, $[0, 2]$
Work Step by Step
(a). $ f(g(x))=2-(x+2)=-x $
Domain: $[-2,\infty)$
Range: $(-\infty, 2]$
(b). $ g(f(x))=\sqrt {2-x^2+2}=\sqrt {4-x^2}$
Domain: $[-2,2]$
Range: $[0, 2]$
