本题精确派宏值很难求出,可以通过下面方法求其尘衡册近试值:
2×1/3+3×1/4+4×1/5+......+99×1/100
=(1-1/2)+(1-1/3)+(1-1/4)+(1-1/5)+......+(1-1/100)-1/2
=98.5-(1/2+1/拦团3+1/4+1/5+......+1/100)
≈98.5-(c-1+㏑100)
≈98.5-0.577215+1-4.60517
=94.317615
≈94.3
注:式中c是欧拉常数:c=0.577215......
也可通过Excel计算其值:
2×1/3+3×1/4+4×1/5+......+99×1/100
=94.31262248236.............
谢谢采纳哦 ^_^