设f(n)=1/(n+1)+1/(n+2)+...+1/2n,则f(n+1)-f(n)等于()我想f(n+1)与f(n)中间的都消掉了,就剩两边一个1/(2n+1)与1/(n+1)了.所以最后应该是1/(2n+1)-1/(n+1).可是为什么错了.
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设f(n)=1/(n+1)+1/(n+2)+...+1/2n,则f(n+1)-f(n)等于()我想f(n+1)与f(n)中间的都消掉了,就剩两边一个1/(2n+1)与1/(n+1)了.所以最后应该是1/(2n+1)-1/(n+1).可是为什么错了.
设f(n)=1/(n+1)+1/(n+2)+...+1/2n,则f(n+1)-f(n)等于()
我想f(n+1)与f(n)中间的都消掉了,就剩两边一个1/(2n+1)与1/(n+1)了.所以最后应该是1/(2n+1)-1/(n+1).可是为什么错了.
设f(n)=1/(n+1)+1/(n+2)+...+1/2n,则f(n+1)-f(n)等于()我想f(n+1)与f(n)中间的都消掉了,就剩两边一个1/(2n+1)与1/(n+1)了.所以最后应该是1/(2n+1)-1/(n+1).可是为什么错了.
f(n+1)=1/(n+1+1)+1/(n+1+2)+...+1/2(n+1)
所以
f(n+1)-f(n)=1/(2n+1)+1/(2n+2)-1/(n+1)
=1/(2n+1)-1/(2n+2)
f(n)=1/(n+1)+1/(n+2)+...+1/(2n)
f(n+1)-f(n)
=1/(n+2)+1/(n+3)+...+1/(2(n+1)) - [1/(n+1)+1/(n+2)+...+1/(2n)]
=1/(2n+1) + 1/(2n+2) -1/(n+1)
=1/(2n+1) - 1/(2n+2)
f(n+1)=1/(n+1+1)+1/(n+1+2)+...+1/2(n+1)
=1/(n+2)+1/(n+3)+...+1/(2n+2)
f(n)=1/(n+1)+1/(n+2)+...+1/2n
f(n+1)-f(n)=1/(2n+1)+1/(2n+2)-1/(n+1)
=1/(2n+1)-1/(2n+2)
=1/(2n+1)1/(2n+2)