Answer
$ f(g(x))=(1-\sqrt x)^{2}$,
Domain: $[0,\infty)$,
Range: $[0,\infty)$
$ g(f(x))=1-|x|$,
Domain: $(-\infty,\infty)$,
Range: $(-\infty,1]$
Work Step by Step
To find the composite function, we plug in the inside function into the "x" value of the outside function:
$f\circ g = f(g(x))=(1-\sqrt x)^{2}$
$g\circ f = g(f(x))=1-\sqrt {x^{2}}=1-|x|$