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问题: 一道高一数学题哦 请高手指点哈

已知数列{An}中,A1=1,A(n+3)小于等于An+3,A(n+2)大于等于An+2,求A2007

解答:

An>=A(n+3)-3
An<=A(n+2)-2
A(n+3)<=A(n+2)+1---A(n+1)<=An+1


A(n+6)>=A(n+4)+2>=A(n+2)+4>=An+6
A(n+6)<=A(n+3)+3<=An+6
A(n+6)=An+6

A2<=2
A3>=A1+2=3
A3<=A2+1<=3
A3=3

A2007=A3+2004=2007