1又1/3+3又1/15+5又1/35+7又1/63+1/99 ...
问题描述:
1又1/3+3又1/15+5又1/35+7又1/63+1/99 ...
答
1又1/3+3又1/15+5又1/35+7又1/63+1/99 =1+3+5+7+1/(1×3)+1/(3×5)+1/(5×7)+1/(7×9)+1/(9×11)=16+1/2×(1-1/3+1/3-1/5+1/5-1/7+1/7-1/9+1/9-1/11)=16+1/2×10/11=16+5/11=16又5/...