Boncic's Identity (Variant of Euler's Identity)

Boncic's Identity:

ei x pi + ei x tau = 0

$\begin{array}{rcll} e^{i\pi}+ e^{i\tau} &\stackrel{?}=& 0 \quad &| \quad \tau = 2=pi \\ e^{i\pi}+ e^{i2\pi} &\stackrel{?}=& 0 \\ e^{i\pi}+ (e^{i\pi})^2 &\stackrel{?}=& 0 \quad &| \quad e^{i\pi} = -1\ (\text{Euler's Identity}) \\ -1+ (-1)^2 &\stackrel{?}=& 0 \\ -1+ 1 &=& 0\ \checkmark \\ \end{array}$