1/1×2+1/2×3+1/3×4+......+1/2006×2007怎么做
来源:百度知道 编辑:UC知道 时间:2024/06/17 02:15:59
请各位哥哥姐姐帮帮我做....谢谢
1/1×2+1/2×3+1/3×4+......+1/2006×2007
=(1-1/2)+(1/2-1/3)+(1/3-1/4)+……+(1/2006-1/2007)
=1-1/2007
=2006/2007
原式=(1/1-1/2)+(1/2-1/3)+(1/3-1/4)+……+(1/2006-1/2007)
中间都抵消掉
=1/1-1/2007
=2006/2007
1/1*2=1-1/2
1/2*3=1/2-1/3
1/3*4=1/3-1/4
…………
1/2006*2007=1/2006-1/2007
原式=1-1/2007=2006/2007
1.
1/1*2+1/2*3+1/3*4+...+1/2006*2007
=[1-1/2+1/2-1/3+1/3-1/4+...+1/2006-1/2007]
中间的都抵消,首尾各剩下一项
=1-1/2007
=2006/2007
原式=(1/1-1/2)+(1/2-1/3)+(1/3-1/4)+……+(1/2006-1/2007)
将括号去掉
=1/1-1/2007
=2006/2007
1+1/(1+2)+1/(1+2+3)+...+1/(1+2+3+...+100)
1+1/(1+2)+1/(1+2+3)+-------+1/(1+2+3+----+100)
1 3 2 1 x
1,1,1,2,3,5,9,()
(3+1)(3^2+1)(3^4+1)...(3^2n+1)+1/2
1+(1+2)+(1+2+3)+(1+2+3+4)+...(1+2+3+...+100)=
1/3+1/5+1/7+~~~~~~1/2n+1
依次计算1,1+2+1,1+2+3+2+1,1+2+3+4+3+2+1,...
1+1/1+2+1/1+2+3+...+1/1+2+3...+2000
1*(1/1+2)*(1/1+2+3)*~~~*(1/1+2+~~~2005)=?