/// <summary>Trigonometric Cotangent (Cotangens) of this <c>Complex</c>.</summary> public Complex Cot() { if (IsReal) { return(new Complex(Trig.Cot(real), 0d)); } double sinr = Trig.Sin(real); double sinhi = Trig.Sinh(imag); double denom = sinr * sinr + sinhi * sinhi; return(new Complex(sinr * Trig.Cos(real) / denom, -sinhi * Trig.Cosh(imag) / denom)); }