Chapter 3 - Second Order Linear Equations - 3.3 Complex Roots of the Characteristic Equation - Problems - Page 163: 6

$\frac{cos(2ln(\pi))}{\pi}+ \frac{isin(2ln(\pi))}{\pi}$

$\pi^{-1+2i} = \frac{1}{\pi}\pi^{2i}$ Applying Euler's formula to $\pi^{2i}$ yields $cos(2ln(\pi))+ isin(2ln(\pi))$ $\frac{cos(2ln(\pi))}{\pi}+ \frac{isin(2ln(\pi))}{\pi}$