A2. The value of the expression $\sqrt{3-\sqrt{5}}+\sqrt{3+\sqrt{5}}$ is
(A) $2 \sqrt{3}$
(B) $\sqrt{10}$
(C) 3.46
(D) 2
(E) $\sqrt{6}$
A2. Let's calculate the value of the square of the expression, that is

$$
\begin{gathered}
(\sqrt{3-\sqrt{5}}+\sqrt{3+\sqrt{5}})^{2}=3-\sqrt{5}+2 \cdot \sqrt{3-\sqrt{5}} \cdot \sqrt{3+\sqrt{5}}+3+\sqrt{5}= \\
=6+2 \sqrt{(3-\sqrt{5})(3+\sqrt{5})}=6+2 \sqrt{9-5}=10
\end{gathered}
$$

so the value of the expression is $\sqrt{10}$.