解
是这个吗
(-1×1/2)+(-1/2×1/3)+(-1/3×1/4)+……+(-1/99×1/100)
=-[(1×1/2)+(1/2×1/3)+……+(1/99×1/100)
=-[(1-1/2)+(1/2-1/3)+(1/3-1/4)+……+(1/99-1/100)
=-[1+(1/2-1/2)+(1/3-1/3)+……+(1/99-1/99)-1/100]
=-(1-1/100)
=-99/100为什么中间突然就变成了=-[(1-1/2)+(1/2-1/3)+(1/3-1/4)+……+(1/99-1/100)呢？我数学不太好，能不能讲详细一点？1×1/2=1-1/21/2×1/3=1/2-1/31/3×1/4=1/3-1/4裂项1/n(n+1)=1/n-1/(n+1)这算一个公式吧