Square roots of −i , where i = √−1, are
\(cos\left(-\frac{\pi}{4}\right)+i\:sin\left(-\frac{\pi}{4}\right), cos\left(\frac{3\pi}{4}\right)+i\:sin\left(\frac{3\pi}{4}\right)\)
Write−i=e⁻ⁱᵖⁱᐟ². Its square roots have angles−π/4 and−π/4+π=3π/4 and unit magnitude. Thus cos(−π/4)+i sin(−π/4) and its negative are the roots.
The contour integral $$\oint_C e^{1/z} dz$$ with C as the counter-clockwise unit circle in the z-plane is equal to
Let $$ I = \int_0^1 \frac{1}{1+t} dt + \frac{\pi i}{2} \int_0^1 \frac{1}{1+e^2} dt - i \int_0^1 \frac{1}{1+it} dt, $$ where $ t $ is a real variable and $ i = \sqrt{-1} $. The value of $ I $ is ______________