1/2+1/(2+3)+1/(2+3+4)+.+1/(2+4+5+...)200)=?
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/11 05:16:41
![1/2+1/(2+3)+1/(2+3+4)+.+1/(2+4+5+...)200)=?](/uploads/image/z/2021941-37-1.jpg?t=1%2F2%2B1%2F%282%2B3%29%2B1%2F%282%2B3%2B4%29%2B.%2B1%2F%282%2B4%2B5%2B...%29200%29%3D%3F)
xa0övC C`^x0Ob;6DMLL#@?`рАj2|M0M(tN
x?i* i}wbq/_2e,(ܬ%&z
VHtU5!6m1ͺBfӏ=&WLny/g/~,`M||Hm70|j#C{Q;ct
1/2+1/(2+3)+1/(2+3+4)+.+1/(2+4+5+...)200)=?
1/2+1/(2+3)+1/(2+3+4)+.+1/(2+4+5+...)200)=?
1/2+1/(2+3)+1/(2+3+4)+.+1/(2+4+5+...)200)=?
1/2+1/(2+3)+1/(2+3+4)+.+1/(2+3+4+5+...200)
=1/2+1/[2*(2+3)/2]+1/[3*(2+4)/2]+……+1/[199*(2+200)/2]
=1/2+2/(2*5)+2/(3*6)+2/(4*7)+……+2/(199*202)
=1/2+2/3(1/2-1/5)+2/3(1/3-1/6)+2/3(1/4-1/7)+……+2/3(1/199-1/202)
=1/2+2/3(1/2-1/5+1/3-1/6+1/4-1/7+1/5-1/8+……+1/199-1/202)
=1/2+2/3(1/2+1/3+1/4-1/200-1/201-1/202)
=1/2+2/3(13/12-30301/2030100)
=1/2+2/3*2168974/2030100
=1/2+2168974/3045150
=3691549/3045150