CommandssinOn this pagesin sin (angle) The sin function returns the sine of angle which is in radians. In complex expressions, angle is complex, and sin(angle) returns a complex value: sin(x+iy)=sin(x)cosh(y)+icos(x)sinh(y).\displaystyle \sin (x+i y)=\sin (x) \cosh (y)+i \cos (x) \sinh (y) .sin(x+iy)=sin(x)cosh(y)+icos(x)sinh(y). See Also asin, cos, tan, sec, csc, cot