sin(z+2π)=sinzcos(z+2π)=cosztan(z+π)=tanz
For complex numbers a,b,z the following holds: (sinz)2+(cosz)2=1 sin(a+b)=sinacosb+cosasinbcos(a+b)=cosacosb−cosacosbsina+sinb=2sin(a+b2)cos(a−b2)cosa+cosb=2cos(a+b2)cos(a−b2)
Real value of sin(x+iy).