即：Sn=(1/2)[An²＋An] >>>> An＋A(n－1)≠0
則：An－A(n－1)=1=常數(shù),即：{An}是以a1=1為首項(xiàng)、以d=1為公差的等差數(shù)列
所以,An=n但是答案是An=n
正數(shù)列An,前n項(xiàng)和Sn是An平方和An的等差中項(xiàng),求An
正數(shù)列An,前n項(xiàng)和Sn是An平方和An的等差中項(xiàng),求An
數(shù)學(xué)人氣：692 ℃時(shí)間：2020-06-18 18:51:11
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