In recent years advances in medical technology have made it possible for people to live longer than in the past. New medicines and machines are developing every day to extend life. However, some people, including some doctors, don't agree with these life extending measures, and they say that people should have the right(权利)t o die when they want, They say that the quality of life is as important as life itself, and that people should not be forced to go on living when conditions of life have become unbearable. They say that people should be allowed to die with dignity(尊严) and to decide when they want to die. Others don't agree and say that life under any conditions is better than death and that the duty of doctors is always to extend life as long as possible. And so the quarrel goes on and on without a definite(明确的) answer.
是定义在R上周期为3的奇函数，若
，则有