(1/2)已知数列an满足条件：a1=1.a2=r.(r>0)且{anan+1}是公比为q的等比数列,设bn=a2n-1+a2n,求数列bn的前

来源：学生作业帮助网编辑：作业帮时间：2024/05/05 19:35:03

(1/2)已知数列an满足条件：a1=1.a2=r.(r>0)且{anan+1}是公比为q的等比数列,设bn=a2n-1+a2n,求数列bn的前
(1/2)已知数列an满足条件：a1=1.a2=r.(r>0)且{anan+1}是公比为q的等比数列,设bn=a2n-1+a2n,求数列bn的前

(1/2)已知数列an满足条件：a1=1.a2=r.(r>0)且{anan+1}是公比为q的等比数列,设bn=a2n-1+a2n,求数列bn的前
an*an+1/an-1*an=q→an+1/an-1=q→an+2/an=q→a(2k+1)=a(2k-1)*q;a(2k)=a(2k-2)*q
a1=1,a2=r→bn=q^(n-1)+r*q^(n-1)→bn=(r+1)*q^(n-1)
∑bn=(r+1)*(q^0+q^1+q^2+...q^(n-1))=(r+1)*(1-q^n)/(1-q)

已知数列an满足条件a1=-2 an+1=2an+1则a5 已知数列an 满足条件a1=-2 an+1=2+2an／（1-an） a5=? 已知数列an满足条件a1=-2 a（n+1）=2an/(1-an) 则an= 已知数列{an}满足条件:a1=5,an=a1+a2+...a(n-1) n大于等于2,求数列{an}的通项公式已知数列{an}满足条件a1=3,且a( n+1)-an=(20)^n+n,求通项公式已知数列{an}满足条件a1=3,且a( n+1)-an=(2)^n+n,求通项公式已知数列{an}满足条件:a1=1,an+1=2an+1,n属于N(1)求证:数列{an+1}为等比数列已知数列{an}满足an+1=2an+3.5^n,a1=6.求an 根据下列条件,确定数列｛An｝的通项公式 1.,A1=1,An+1=(n+1)An,求An2已知数列｛an｝满足a(n+1)=an+n且a1=2,求an 已知数列an满足an=1+2+...+n,且1/a1+1/a2+...+1/an 已知数列满足a1=1 ,an+1+2an=2 求an 已知数列{an}满足a1=1,an+1·an=2^n 则s2012 已知数列{an}满足An+1=2^nAn,且A1=1,则通项an 已知数列{an}满足a1=1/2,sn=n^2an,求通项an 已知数列{an},满足a1=1/2,Sn=n²×an,求an 已知数列an满足a1=1/2 sn=n平方×an 求an 已知数列An满足 A1=1/2 Sn=N²An 求An 已知数列an满足an+1=nan,a1=2,求an通项已知数列an满足a1=1 Sn=2an+n 求an