Use identities to simplify $lg(a^2+b^2)^2$ Use logarithmic identities to simply the following:
$$lg(a^2+b^2)^2$$
I started with
\begin{eqnarray}
lg(a^2+b^2)^2&=&2 \cdot lg(a^2+b^2) \\
\end{eqnarray}
I think it's not the final result, but I don't know how to proceed. Any hints would be helpful.

$$\lg(a^2+b^2)^2=2 \cdot \lg(a^2+b^2)=2 \biggr( \lg(a+ib)+\lg(a-ib) \biggr)  $$
