等差数列题目S(n+1)/Sn=(n+2)/n,求An

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等差数列题目S(n+1)/Sn=(n+2)/n,求An

等差数列题目S(n+1)/Sn=(n+2)/n,求An
等差数列题目
S(n+1)/Sn=(n+2)/n,求An

等差数列题目S(n+1)/Sn=(n+2)/n,求An
当n=1时代入上式,则有 (A1+A2)/A1=3/2
∴A2=2A1 公差d=A2-A1=A1
∴An=A1+(n-1)d=nA1

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