code: public static ComplexNumber Sin(ComplexNumber z1) {
          ComplexNumber result = new ComplexNumber();
  
          if (z1.imaginary == 0.0) {
              result.real = Math.sin(z1.real);
              result.imaginary = 0.0;
          } else {
              result.real = Math.sin(z1.real) * Math.cosh(z1.imaginary);
              result.imaginary = Math.cos(z1.real) * Math.sinh(z1.imaginary);
          }
  
          return result;
      }
docs: Calculates Sine value of the complex number.
  
  @param z1 A Complex Number instance.
  @return Returns new ComplexNumber instance containing the Sine value of the specified complex number.