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a1=2p,an=2p-p^2/an-1p为常数求a2a3a4猜想an的通项公式,并证明···························有分追加········吖········是a(n-1)

题目详情
a1=2p,an=2p-p^2/an-1 p为常数求a2a3a4 猜想an的通项公式,并证明
···························有分追加········吖········是a(n-1)
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答案和解析
a1=2p
a2=2p-p²/a1=2p-p²/2p=3/2*p
a3=2p-p²/a2=2p-2p²/3p=4/3*p
a4=2p-p²/a3=2p-3p²/4p=5/4*p
猜想an=(n+1)/n*p(n∈正整数),且a1,a2,a3,a4均成立
假设an成立,那么a(n+1)=2p-p²/an=2p-p²n/(n+1)p=2p-np/(n+1)=(n+2)/(n+1)*p
所以a(n+1)也成立
根据数学归纳法,所以an=(n+1)/n*p(n∈正整数)