Answer
$G(x)=\sqrt {3x}=(g \circ f)(x)$
Work Step by Step
$f(x)=3x$
$g(x)=\sqrt x$
$G(x)=\sqrt {3x}$. So
$G(x)=\sqrt {f(x)}=g(f(x))=(g \circ f)(x)$.
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