Question 905093
(b)


{{{f(x) = sqrt(x+3)}}}


{{{f(g(x)) = sqrt(g(x)+3)}}} replace EVERY x with g(x)


{{{f(g(x)) = sqrt(x^2+3+3)}}} replace g(x) on the right side with {{{x^2+3}}}


{{{f(g(x)) = sqrt(x^2+6)}}}


which is the answer to part (b)


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(d)



{{{f(x) = sqrt(x+3)}}}


{{{f(f(x)) = sqrt(f(x)+3)}}} replace EVERY x with f(x)


{{{f(f(x)) = sqrt(sqrt(x+3)+3)}}} replace f(x) on the right side with {{{sqrt(x+3)}}}


{{{f(f(x)) = sqrt(3+sqrt(x+3))}}}


and you're done