Composition of a function

Question

Hello:

 

I need help with this question

Express the function y=sqrt x^2 +3  as a composition

y=f(g(x)) of two single functions

y=f(u) and u=g(x)

 

Thank you

Answer 1

Let f(u) = u + 3,    u = g(x) = x²

 

Then, f(g(x)) = f(x²) = x² + 3