已知等比数列an满足an大于0,n=1,2.且a5乘a2n-5=2的2n(n大于等于3)
来源:学生作业帮 编辑:作业帮 分类:数学作业 时间:2024/10/04 10:56:24
已知等比数列an满足an大于0,n=1,2.且a5乘a2n-5=2的2n(n大于等于3)
已知等比数列{an}满足an>0,n=1,2,…,且a5-a2n-5=2^2n(n>=3),且当n>=1时,
log 2 a1+log 2 a3+…log 2 a2n-1=
已知等比数列{an}满足an>0,n=1,2,且a(5)乘a(2n-5)=2^2n(n>=3),且当n>=1时,
log 2 a1+log 2 a3+…+log 2 a2n-1=
已知等比数列{an}满足an>0,n=1,2,…,且a5-a2n-5=2^2n(n>=3),且当n>=1时,
log 2 a1+log 2 a3+…log 2 a2n-1=
已知等比数列{an}满足an>0,n=1,2,且a(5)乘a(2n-5)=2^2n(n>=3),且当n>=1时,
log 2 a1+log 2 a3+…+log 2 a2n-1=
a(5)乘a(2n-5)=2^2n
利用等比数列的性质
a(5)乘a(2n-5)=a1*a(2n-1)=2^(2n)
log 2 a1+log 2 a3+…+log 2 a2n-1 共n项
=log2 [a1*a3.a(2n-1)]
=(1/2)log2 [a1*a3.a(2n-1)]²
=(1/2)log2 [a1*a(2n-1)]^n
=(1/2)log2 [2^(2n)]^n
=(1/2)*(2n²)
=n²
利用等比数列的性质
a(5)乘a(2n-5)=a1*a(2n-1)=2^(2n)
log 2 a1+log 2 a3+…+log 2 a2n-1 共n项
=log2 [a1*a3.a(2n-1)]
=(1/2)log2 [a1*a3.a(2n-1)]²
=(1/2)log2 [a1*a(2n-1)]^n
=(1/2)log2 [2^(2n)]^n
=(1/2)*(2n²)
=n²
已知等比数列{an}中满足an大于0,n为正整数且a5*a2n-5=2的2n次方则n大于等于1时,loga1+loga2
已知数列{an}的首项a1=1,且{an}满足an=n(n+an-1),其中n大于等于2,求{an}的通项
已知数列{an}满足a1=1且an=1/3an-1+(1/3)^n(n大于等于2,且n属于N*)则数列(an)的通项公式
数列{an}满足an=3an-1+3的n次方-1(n属于正整数,n大于等于2),已知a3=95
已知数列{an}的前n项和为Sn,且满足a1=1,2an/(anSn-Sn^2)=1(n大于等于2)
已知数列(an)满足:a1=3,an=2 a(n-1)+ 2的n次方 -1 (n大于等于2)
已知数列an的前n项和为sn,4sn=an^2+2an-3,若a1,a2,a3成等比数列,且n大于等于3时a大于0.(1
已知数列{an}的前n项和满足a1=1/2,an=-Sn*S(n-1),(n大于或等于2),求an,Sn
已知数列{An}满足=2An-1+2^n-1(n属于正整数,n大于等于2)且A4=81.求数列{An
数列{An}满足a1=1,且An=2An-1+2^n(n大于等于2且n属于整数).求数列的通项公式
已知数列{an}满足a1=b,an=nban-1/an-1+n-1(n大于等于2),求数列an的通项公式
已知公差大于零的等差数列an前n项和为Sn,且满足a3a4=-3,a2+a5=2.(1)求通项a