利用裂项法求解 1*3/1+3*5/1+5*7/1+.+99*101/1 (*为乘号)写反了,应该是:1/1*3+1/3*5+1/5*7+.....+1/99*101

问题描述:

利用裂项法求解 1*3/1+3*5/1+5*7/1+.+99*101/1 (*为乘号)
写反了,应该是:
1/1*3+1/3*5+1/5*7+.....+1/99*101

原式=1/2(1-1/3)+1/2(1/3-1/5)+。。。。。。+1/2(1/99-1/101)
=1/2(1-1/101)
=1/2*100/101
=50/101


希望能帮助到你!

1/1*3=1/2(1/1-1/3)
1/3*5=1/2(1/3-1/5)
1/1*3+1/3*5+1/5*7+......+1/99*101
=1/2(1/1-1/3+1/3-1/5+......+1/99-1/101)
=1/2(1/1-1/101)
50/101

神之问客,
1/1×3+1/3×5+1/5×7+...+1/99×100
=1/2×(1-1/3+1/3-1/5+1/5-1/7+...+1/99-1/100)
=1/2×(1-1/100)
=1/2×99/100
=99/200

jhk j