\[\begin{aligned} &(-1)^{\pi}=? \\\\ &\begin{aligned} e^{i \theta} &=\cos \theta+i \sin \theta \\\\ e^{i \pi} &=\cos \pi+i \sin \pi \\\\ &=-1 \end{aligned} \\\\ &\begin{aligned} (-1)^{\pi} &=\left(e^{i \pi}\right)^{\pi} \\\\ &=e^{i \pi^{2}} \\\\ &=\cos \pi^{2}+i \sin \pi^{2} \\\\ & \simeq-0.903-(0.430) i \end{aligned} \end{aligned}\]