code: public static double sin(double radians) {
  		radians = reduceSinAngle(radians); // limits angle to between -PI/2 and +PI/2
  		if (Math.abs(radians) <= Math.PI / 4) {
  			return Math.sin(radians);
  		} else {
  			return Math.cos(Math.PI / 2 - radians);
  		}
  	}
docs: Get the sine of an angle
  
  @param radians The angle
  @return The sine of the angle