1/(1x2x3)+1/(2x3x4)+1/(3x4x5)+.1/(nx(n+1)x(n+2)=?请问这个题目该怎么思考,我经常碰到,可一碰到新的就无从下手.请高手教教我方法
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/25 10:53:51
![1/(1x2x3)+1/(2x3x4)+1/(3x4x5)+.1/(nx(n+1)x(n+2)=?请问这个题目该怎么思考,我经常碰到,可一碰到新的就无从下手.请高手教教我方法](/uploads/image/z/614916-36-6.jpg?t=1%2F%281x2x3%29%2B1%2F%282x3x4%29%2B1%2F%283x4x5%29%2B.1%2F%28nx%28n%2B1%29x%28n%2B2%29%3D%3F%E8%AF%B7%E9%97%AE%E8%BF%99%E4%B8%AA%E9%A2%98%E7%9B%AE%E8%AF%A5%E6%80%8E%E4%B9%88%E6%80%9D%E8%80%83%2C%E6%88%91%E7%BB%8F%E5%B8%B8%E7%A2%B0%E5%88%B0%2C%E5%8F%AF%E4%B8%80%E7%A2%B0%E5%88%B0%E6%96%B0%E7%9A%84%E5%B0%B1%E6%97%A0%E4%BB%8E%E4%B8%8B%E6%89%8B.%E8%AF%B7%E9%AB%98%E6%89%8B%E6%95%99%E6%95%99%E6%88%91%E6%96%B9%E6%B3%95)
1/(1x2x3)+1/(2x3x4)+1/(3x4x5)+.1/(nx(n+1)x(n+2)=?请问这个题目该怎么思考,我经常碰到,可一碰到新的就无从下手.请高手教教我方法
1/(1x2x3)+1/(2x3x4)+1/(3x4x5)+.1/(nx(n+1)x(n+2)=?
请问这个题目该怎么思考,我经常碰到,可一碰到新的就无从下手.请高手教教我方法
1/(1x2x3)+1/(2x3x4)+1/(3x4x5)+.1/(nx(n+1)x(n+2)=?请问这个题目该怎么思考,我经常碰到,可一碰到新的就无从下手.请高手教教我方法
=1/2×[1/1×2-1/2×3+1/2×3-1/3×4+……+1/n(n+1)-1/(n+1)(n+2)]
=1/2×[1/1×2-1/(n+1)(n+2)]
=1/4-2/(4n²+12n+8)
=(n²+3n)/(4n²+12n+8)
1x2x3+2x3x4+...+nxx=?
1/1x2x3+1/2x3x4+.+1/98x99x100 .
1/1X2X3+1/2X3x4+…+1/48X49X50
1X2X3+2X3X4+.+n(n+1)(n+2)
1x2x3+2x3x4+.+nx(n+1)(n+2)=?
1x2x3+2x3x4+.+n(n+1)(n+2)=?
求和1x2x3+2x3x4+...+n(n+1)(n+2)
1x2x3+2x3x4+…+n(n+1)
1x2x3+2x3x4+3x4x5+…+8x9x10
1x2x3+2x3x4+3x4x5+.+10x11x12
1x2x3+2x3x4+3x4x5+...+7x8x9=,
1x2X3+2x3X4+3x4X5+…+7X8X9=?
1x2x3 2x3x4 3x4x5 .10x11x12,怎么算
求和:1X2X3+2X3X4+3X4X5+...+98X99X100
计算1x2x3+2x3x4+…+48x49x50
1x2=1|3(1x2x3-0x1x2) 2x3=1|3(2x3x4-1x2x3) 3x4=1|3(3x4x5-2x3x4)由此推断1x2x3+2x3x4+3x4x5.7x8x9=?
1x2=1/3x(1x2x3-0x1x2)2x3=1/3x(2x3x4-1x2x3)3x4=1/3x(3x4x5-2x3x4)求1x2x3+2x3x4+3x4x5+...+7x8x9=?
1/1x2x3+1/2x3x4+1/3x4x51/2x3x4 + 1/3x4x5 + 1/4x5x6 +……+1/99x100x101是 1/(2x3x4)