Q

i to the - i

$\mathrm{i}^{\mathrm{-i}}=\left(\mathrm{e}^{\mathrm{i} \ \frac{\pi}{2} }\right)^{\mathrm{-i}}=\mathrm{e}^{\mathrm{-i}^{2} \frac{\pi}{2} }=\mathrm{e}^{\frac{\pi}{2}}$