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.