code: public static BigComplex tan(BigComplex x, MathContext mathContext) {
  		MathContext mc = new MathContext(mathContext.getPrecision() + 4, mathContext.getRoundingMode());
  
  		return sin(x, mc).divide(cos(x, mc), mc).round(mathContext);
  	}
docs: Calculates the tangens of {@link BigComplex} x in the complex domain.
  
  @param x the {@link BigComplex} to calculate the tangens for
  @param mathContext the {@link MathContext} used for the result
  @return the calculated tangens {@link BigComplex} with the precision specified in the <code>mathContext</code>