Gamma(z)Gamma(1-z)=pi/sin(pi z)
From specialfunctionswiki
(Redirected from Euler's reflection formula for gamma)
The following formula holds: $$\Gamma(z)\Gamma(1-z) = \dfrac{\pi}{\sin(\pi z)},$$ where $\Gamma$ denotes the gamma function and $\sin$ denotes the sine function.
