In the arithmetic sequence {an}, Sn is the sum of the first n terms, and S7 is the largest, the largest positive integer n of | A7 | 0? There seem to be two answers, one is 12 and the other is 13-
Let the tolerance be D and the first item be a
The general term an = a + (n-1) d
There is a maximum value of Sn, so a > 0, d0
a8=a+7d
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- 2. If we know that A3 = 2, a7 = 1 in {an} and that {an} is an arithmetic sequence, then A8 =?
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