设f(n)=1-1/2+1/3-1/4+...+1/(2n-1)-1/2n,则f(k+1)-f（k)的值为
问题描述：
设f(n)=1-1/2+1/3-1/4+...+1/(2n-1)-1/2n,则f(k+1)-f（k)的值为
答
1/(2k+1)-1/(2k+2)过程？？f(k+1)=1-1/2+1/3-1/4+...+1/(2k-1)-1/2k+1/(2k+1)-1/(2k+2)f(k)=1-1/2+1/3-1/4+...+1/(2k-1)-1/2k上下两式相减就有f(k+1)-f(k)=1/(2k+1)-1/(2k+2)