已知数列an满足 a1=0,an+1=根号3倍的an再加1 分之an-根号3,n属于n*则a20等于?
人气:160 ℃ 时间:2019-08-21 00:48:26
解答
a1=0
a2=-√3
a3=(-√3-√3)/(-2)=√3
a4=(√3-√3)/4=0
……
规律:从第一项开始,每3个按0,-√3,√3循环一次.
20/3=6余2
第20项a20=-√3
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