谁能帮忙做一下,万分感谢!
2个回答
展开全部
设s1=1+1/2+1/3.......+1/1999;
s2=1/1000+1/1001....1/1999;
s3=1-1/2+1/3-1/4+...1/1999;
s4=1/2000+1/2002+1/2004+...+1/3998
n=(1-1/2+1/3-1/4+...+1/1999)/(1/2000+1/2002+1/2004+...+1/3998)
显然n=s3/s4且s4=s2/2
另外:
s4=1-1/2+1/3-1/4+...+1/1999
=1+(1/2-2/2)+1/3+(1/4-2/4).....+(1/1998-2/1998)+1/1999
=1+1/2+1/3+1/4.....1/1999-(2/2+2/4+2/8.....+2/1998)
=s1-(1+1/2+1/3+1/4+...1/999)
=s1+(s1-s2)=s2
则原题的值为:
n=s4/s3=2
s2=1/1000+1/1001....1/1999;
s3=1-1/2+1/3-1/4+...1/1999;
s4=1/2000+1/2002+1/2004+...+1/3998
n=(1-1/2+1/3-1/4+...+1/1999)/(1/2000+1/2002+1/2004+...+1/3998)
显然n=s3/s4且s4=s2/2
另外:
s4=1-1/2+1/3-1/4+...+1/1999
=1+(1/2-2/2)+1/3+(1/4-2/4).....+(1/1998-2/1998)+1/1999
=1+1/2+1/3+1/4.....1/1999-(2/2+2/4+2/8.....+2/1998)
=s1-(1+1/2+1/3+1/4+...1/999)
=s1+(s1-s2)=s2
则原题的值为:
n=s4/s3=2
推荐律师服务:
若未解决您的问题,请您详细描述您的问题,通过百度律临进行免费专业咨询