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