1/2-1/6-1/12-1/20-1/30-1/42-···-1/132

问题描述:

1/2-1/6-1/12-1/20-1/30-1/42-···-1/132

1/2-1/6-1/12-1/20-1/30-1/42-···-1/132=(1-1/2)-(1/2-1/3)-(1/3-1/4)-(1/4-1/5)-(1/5-1/6)-(1/6-1/7)-...-(1/11-1/12)=(1-1/2-1/2)+1/3-1/3+1/4-1/4+1/5-1/5+1/6-1/6+1/7-.-1/11+1/12=0+1/12=1/...