code: public static void sqrt(Complex_F64 input, Complex_F64 root)
      {
          double r = input.getMagnitude();
          double a = input.real;
  
          root.real = Math.sqrt((r+a)/2.0);
          root.imaginary = Math.sqrt((r-a)/2.0);
          if( input.imaginary < 0 )
              root.imaginary = -root.imaginary;
      }
docs: Computes the square root of the complex number.
  
  @param input Input complex number.
  @param root Output. The square root of the input