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单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,*,6.1 数列的概念与表示,1,6.1 数列的概念与表示 1,2,2,3,3,4,4,5,5,6,6,题型,1,知数列前几项求通项公式,7,题型1知数列前几项求通项公式7,8,8,9,9,10,10,11,11,12,12,13,13,题型,2,由,a,n,与,S,n,的关系求通项公式,14,题型2由an与Sn的关系求通项公式14,15,15,16,16,17,17,2024/8/29,18,2023/9/418,19,19,20,20,21,21,22,22,23,23,题型,3,由递推关系求通项公式,角度,1,形如,a,n,1,a,n,f,(,n,),,求,a,n,累加法,累乖法,24,题型3 由递推关系求通项公式角度1形如an1anf(,25,25,26,26,27,27,待定系数法、转化法、构造法,角度,3,形如,a,n,1,pa,n,q,,求,a,n,角度,4,形如,a,n,1,pa,n,qb,n,,求,a,n,28,待定系数法、转化法、构造法角度3形如an1panq,,29,29,30,30,31,31,32,32,(2),已知在数列,a,n,中,a,1,=,1,a,n+,1,=,2,a,n,+,3,n,则数列的通项公式,a,n,=,.,33,(2)已知在数列an中,a1=1,an+1=2an+3n,(2),由,a,n+,1,=,2,a,n,+,3,n,得,a,n+,1,-,3,n+,1,=,2(,a,n,-,3,n,),.,所以数列,a,n,-,3,n,是首项为,a,1,-,3,1,=-,2,q=,2,的等比数列,所以,a,n,-,3,n,=-,2,2,n-,1,即,a,n,=,3,n,-,2,n,.,34,(2)由an+1=2an+3n,得an+1-3n+1=2(a,2024/8/29,35,2023/9/435,
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