数列an,a1=1.an+1/an=n+2/n,求通项公式,

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数列an,a1=1.an+1/an=n+2/n,求通项公式,数列an,a1=1.an+1/an=n+2/n,求通项公式,数列an,a1=1.an+1/an=n+2/n,求通项公式,因为a1=1,a(n

数列an,a1=1.an+1/an=n+2/n,求通项公式,
数列an,a1=1.an+1/an=n+2/n,求通项公式,

数列an,a1=1.an+1/an=n+2/n,求通项公式,
因为a1=1,a(n+1)/an=(n+2)/n
所以 an=(n+1)/(n-1)*a(n-1)=(n+1)/(n-1)*n/(n-2)*a(n-2)=.
=(n+1)/(n-1)*n/(n-2)*.*4/2*3/1*a1
=(n+1)n/(2*1)*1
=n(n+1)/2

an=n(n+1)/2