是不是证明此等式成立?1/2∑1/k - ∑1/k + 1/2∑1/k =1/4 - 1/(n+1) + 1/2(n+1) + 1/2(n+2)
_________n_____ n+1________n+2
证明:1/2∑1/k - ∑1/k + 1/2∑1/k
_______k=1_____ k=2______ k=3
__________________n ___________n ______________________n
=(1/2)*(1/1+1/2+ ∑1/k)-[(1/2+∑1/k + 1/(n+1)]+(1/2)*[∑1/k+
_________________k=3 _________k=3 ____________________k=3
1/(n+1)+1/(n+2)]
=3/4 -1/2 - 1/(n+1) +1/[2(n+1)] +1/[2(n+2)]
式子打不好,但问题不大,就是k=?这里我打的时候对齐了,提交后又对不齐,你按次序对一下吧.