[(1+2)/2]*[(1+2+3)/(2+3)]*[(1+2+3+4)/(2+3+4)]*......*[(1+2+3+......+50)/(2+3+......+50)]

来源:百度知道 编辑:UC知道 时间:2024/09/21 17:35:55

(1+2+3+......+n)/(2+3+......+n)
=[n(n+1)/2]/[n(n+1)/2-1]
=(n^2+n)/(n^2+n-2)
=n(n+1)/(n+2)(n-1)

所以[(1+2)/2]*[(1+2+3)/(2+3)]*[(1+2+3+4)/(2+3+4)]*......*[(1+2+3+......+50)/(2+3+......+50)]
=(2*3/1*4)*(3*4/2*5)(4*5/3*6)......(49*50/48*51)(50*51/49*52)
=3*50/52
=75/26

[(1+2)/2]*[(1+2+3)/(2+3)]*[(1+2+3+4)/(2+3+4)]*......*[(1+2+3+......+50)/(2+3+......+50)]
=[2*3/4*1]*[3*4/5*2]*[4*5/6*3]*......*[50*51/52*49]
=3*50/52
=150/52
=75/26