Suppose that the functions $u$ and $w$ are defined as follows.
\[
\begin{array}{l}
u(x)=x^{2}+1 \\
w(x)=\sqrt{x+6}
\end{array}
\]
Find the following.
\[
\begin{array}{l}
(u \circ w)(3)= \\
(w \circ u)(3)=
\end{array}
\]

Step 1 ：Define the functions $u$ and $w$ as $u(x)=x^{2}+1$ and $w(x)=\sqrt{x+6}$ respectively.

Step 2 ：The notation $(u \circ w)(x)$ means $u(w(x))$, and $(w \circ u)(x)$ means $w(u(x))$.

Step 3 ：To find $(u \circ w)(3)$, we first need to find $w(3)$ and then substitute that into $u(x)$.

Step 4 ：To find $(w \circ u)(3)$, we first need to find $u(3)$ and then substitute that into $w(x)$.

Step 5 ：Calculate $w(3)$: $w(3)=\sqrt{3+6}=\sqrt{9}=3$

Step 6 ：Substitute $w(3)$ into $u(x)$: $u(w(3))=u(3)=(3)^{2}+1=10$

Step 7 ：So, $(u \circ w)(3)= \boxed{10}$

Step 8 ：Calculate $u(3)$: $u(3)=(3)^{2}+1=10$

Step 9 ：Substitute $u(3)$ into $w(x)$: $w(u(3))=w(10)=\sqrt{10+6}=\sqrt{16}=4$

Step 10 ：So, $(w \circ u)(3)= \boxed{4}$