1个回答
展开全部
解:设=1/5+1/7...1/2009+1/2011=X
=(1/3+1/5+1/7...1/2009+1/2011)(1/5+1/7+1/9....+1/2013)-(1/3+1/5...+1/2013)(1/5+1/7..1/2011)
=(1/3+X)(X+1/2013)-(1/3+X+1/2013)X
=X^2 +(1/3)X+(1/2013)X+(1/3)*(1/2013)-X^2 -(1/3)X-(1/2013)X
=(1/3)*(1/2013)=1/6039
=(1/3+1/5+1/7...1/2009+1/2011)(1/5+1/7+1/9....+1/2013)-(1/3+1/5...+1/2013)(1/5+1/7..1/2011)
=(1/3+X)(X+1/2013)-(1/3+X+1/2013)X
=X^2 +(1/3)X+(1/2013)X+(1/3)*(1/2013)-X^2 -(1/3)X-(1/2013)X
=(1/3)*(1/2013)=1/6039
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