计算:1/(1*3*5)+1/(3*5*7)+1/(5*7*9)+...+1/(2003+2005+2007)=?

来源:学生作业帮助网 编辑:作业帮 时间:2024/05/11 20:12:52
计算:1/(1*3*5)+1/(3*5*7)+1/(5*7*9)+...+1/(2003+2005+2007)=?

计算:1/(1*3*5)+1/(3*5*7)+1/(5*7*9)+...+1/(2003+2005+2007)=?
计算:1/(1*3*5)+1/(3*5*7)+1/(5*7*9)+...+1/(2003+2005+2007)=?

计算:1/(1*3*5)+1/(3*5*7)+1/(5*7*9)+...+1/(2003+2005+2007)=?
通项是1/(2n-1)(2n+1)(2n+3)=1/4[1/(2n-1)(2n+1)-1/(2n+1)(2n+3)],于是原式就变成了1/4(1/3-1/15+1/15-1/35……+1/2003*2005-1/2005*2007)=1/4(1/3-1/2005*2007),后面的就不用我算了吧.