标题: 请教寂静一题。多 [打印本页] 作者: 刘民 时间: 2010-11-22 01:07 标题: 请教寂静一题。多 181S: 假设有一个数列S(n),已知S(0),求S(n), 1) S(i) is i more than s(i-1) for any i>=1 2)the difference between S(i) and S(i-1) is i^2 条件一可求 S(i)=s(i-1)+i 条件二不可求无法确定是怎么样的数列 选A
I am not sure whether (2) tells us enough information to solve for S(n). Because (2) says: S(i) = S(i-1) + i^2, then, finally, we can solve s(i) from S(0). Did I miss anything here? Tons thanks. 作者: efrenreyes 时间: 2010-11-22 03:29
条件2：可能是S(i) = S(i-1) + i^2，也可能是S(i-1) = S(i) + i^2，故不充分。作者: fudanwyh 时间: 2010-11-22 03:51
really tricky...作者: 刘民 时间: 2010-11-22 04:25
Thanks a lot.
S: 假设有一个数列S(n),已知S(0),求S(n),