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数列满足An+1=An/(3-2An).A1=1/4,求An通项公式.左边的1是小1.
人气:195 ℃ 时间:2020-03-26 03:08:07
解答
An+1(3-2An)=An
=>
-2An+1An + 3An+1 - An = 0
=>
-2 + 3/An - 1/An+1 = 0
=>
(1/An+1 - 1) = 3(1/An - 1)
=>
1/An - 1 = 3^(n-1)*(1/A1 - 1) = 3^n
=>
An = 1/(3^n + 1)
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