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complex analysis

De Moivre's Theorem

(cosx+isinx)n=cos(nx)+isin(nx)\small (\cos x+ i \sin x)^n=\cos(nx)+i\sin(nx)

Hyperbolic Functions

sinh(x)=exex2\sinh(x) = \frac{e^x - e^{-x}}{2}

Cauchy's Integral Theorem

Cf(z)dz=0\oint_C f(z)dz = 0

Euler's Identity/Formula

eiπ=1e^{i\pi} = -1

Trig functions in terms of e

sin(x)=eixeix2i,cos(x)=eix+eix2\small{\sin(x) = \frac{e^{ix} - e^{-ix}}{2i}, \cos(x) = \frac{e^{ix} + e^{-ix}}{2}}