/// <summary>
/// 复数的幂
/// </summary>
public static Complex Pow(Complex c, double exp)
{
double mod = Math.Pow(c.GetModSqr(), exp * 0.5),
arg = c.GetArgument() * exp;
double re = mod * Math.Cos(arg),
im = mod * Math.Sin(arg);
return new Complex(re, im);
}