Express the function y = sqrt(x2 + 5) as a composition y = f(g(x)) of two simpler functions y = f(u) and u = g(x).

Step 1: Identify the inner function $g(x)$ as $\sqrt{x}$.

$g(x) = \sqrt{x}$

Step 2: Define the outer function $f(u)$ to complete the expression.

$f(u) = u + 8$

Step 3: Verify the composition $f(g(x))$.

$f(g(x)) = g(x) + 8 = \sqrt{x} + 8$

This matches the original function $y = \sqrt{x} + 8$.

Final answer:

$\boxed{ f(u) = u + 8 \\ g(x) = \sqrt{x} }$