Solution
= Solution
Since the arguments of $-1$ are $(2k+1)\pi$, the <complex logarithm> has values $\boxed{\log(-1)=i(2k+1)\pi}$ for $k\in\mathbb Z$. The principal value is $\boxed{i\pi}$.
= Solution
Since the arguments of $-1$ are $(2k+1)\pi$, the <complex logarithm> has values $\boxed{\log(-1)=i(2k+1)\pi}$ for $k\in\mathbb Z$. The principal value is $\boxed{i\pi}$.