已知數(shù)列中.是公比為()的等比數(shù)列.又設(shè). 查看更多

 

題目列表(包括答案和解析)

已知數(shù)列{2an-1}是公比為3的等比數(shù)列,且a1=1,n∈N*
(Ⅰ)求數(shù)列{an}的通項(xiàng)公式;
(Ⅱ)若數(shù)列{bn}的前n項(xiàng)和Sn滿足Sn=2n2+2n-2,且cn=(an-
12
)•bn,求數(shù)列{cn}的前n項(xiàng)和Tn

查看答案和解析>>

已知數(shù)列{an}滿足:a1=1,a2=a(a>0),數(shù)列{bn}滿足bn=anan+1(n∈N*
(Ⅰ)若{an}是等差數(shù)列,且b3=12,求數(shù)列{an}的通項(xiàng)公式.
(Ⅱ)若{an}是等比數(shù)列,求數(shù)列{bn}的前n項(xiàng)和Sn
(Ⅲ)若{bn}是公比為a-1的等比數(shù)列時(shí),{an}能否為等比數(shù)列?若能,求出a的值;若不能,請(qǐng)說(shuō)明理由.

查看答案和解析>>

已知數(shù)列{an}滿足:a1=1,a2=a(a>0),數(shù)列{bn}滿足bn=anan+1(n∈N*
(Ⅰ)若{an}是等差數(shù)列,且b3=12,求數(shù)列{an}的通項(xiàng)公式.
(Ⅱ)若{an}是等比數(shù)列,求數(shù)列{bn}的前n項(xiàng)和Sn
(Ⅲ)若{bn}是公比為a-1的等比數(shù)列時(shí),{an}能否為等比數(shù)列?若能,求出a的值;若不能,請(qǐng)說(shuō)明理由.

查看答案和解析>>

已知數(shù)列{an}滿足:a1=1,a2=a(a>0),數(shù)列{bn}滿足bn=anan+1(n∈N*
(Ⅰ)若{an}是等差數(shù)列,且b3=12,求數(shù)列{an}的通項(xiàng)公式.
(Ⅱ)若{an}是等比數(shù)列,求數(shù)列{bn}的前n項(xiàng)和Sn
(Ⅲ)若{bn}是公比為a-1的等比數(shù)列時(shí),{an}能否為等比數(shù)列?若能,求出a的值;若不能,請(qǐng)說(shuō)明理由.

查看答案和解析>>

已知數(shù)列{an}滿足:a1=1,a2=a(a>0),數(shù)列{bn}滿足bn=anan+1(n∈N*
(Ⅰ)若{an}是等差數(shù)列,且b3=12,求數(shù)列{an}的通項(xiàng)公式.
(Ⅱ)若{an}是等比數(shù)列,求數(shù)列{bn}的前n項(xiàng)和Sn
(Ⅲ)若{bn}是公比為a-1的等比數(shù)列時(shí),{an}能否為等比數(shù)列?若能,求出a的值;若不能,請(qǐng)說(shuō)明理由.

查看答案和解析>>


同步練習(xí)冊(cè)答案