己知数列{an}是首项a1=1/2,公比q=1/2的等比数列,设bn+2=3log1/2an,数列{Cn}满足Cn=an*bn.(1)...己知数列{an}是首项a1=1/2,公比q=1/2的等比数列,设bn+2=3log1/2an,数列{Cn}满足Cn=an*bn.(1)求证:{b
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![己知数列{an}是首项a1=1/2,公比q=1/2的等比数列,设bn+2=3log1/2an,数列{Cn}满足Cn=an*bn.(1)...己知数列{an}是首项a1=1/2,公比q=1/2的等比数列,设bn+2=3log1/2an,数列{Cn}满足Cn=an*bn.(1)求证:{b](/uploads/image/z/3198374-62-4.jpg?t=%E5%B7%B1%E7%9F%A5%E6%95%B0%E5%88%97%EF%BD%9Ban%EF%BD%9D%E6%98%AF%E9%A6%96%E9%A1%B9a1%3D1%2F2%2C%E5%85%AC%E6%AF%94q%3D1%2F2%E7%9A%84%E7%AD%89%E6%AF%94%E6%95%B0%E5%88%97%2C%E8%AE%BEbn%2B2%3D3log1%2F2an%2C%E6%95%B0%E5%88%97%EF%BD%9BCn%EF%BD%9D%E6%BB%A1%E8%B6%B3Cn%3Dan%2Abn.%EF%BC%881%EF%BC%89...%E5%B7%B1%E7%9F%A5%E6%95%B0%E5%88%97%EF%BD%9Ban%EF%BD%9D%E6%98%AF%E9%A6%96%E9%A1%B9a1%3D1%2F2%2C%E5%85%AC%E6%AF%94q%3D1%2F2%E7%9A%84%E7%AD%89%E6%AF%94%E6%95%B0%E5%88%97%2C%E8%AE%BEbn%2B2%3D3log1%2F2an%2C%E6%95%B0%E5%88%97%EF%BD%9BCn%EF%BD%9D%E6%BB%A1%E8%B6%B3Cn%3Dan%2Abn.%EF%BC%881%EF%BC%89%E6%B1%82%E8%AF%81%EF%BC%9A%EF%BD%9Bb)
己知数列{an}是首项a1=1/2,公比q=1/2的等比数列,设bn+2=3log1/2an,数列{Cn}满足Cn=an*bn.(1)...己知数列{an}是首项a1=1/2,公比q=1/2的等比数列,设bn+2=3log1/2an,数列{Cn}满足Cn=an*bn.(1)求证:{b
己知数列{an}是首项a1=1/2,公比q=1/2的等比数列,设bn+2=3log1/2an,数列{Cn}满足Cn=an*bn.(1)...
己知数列{an}是首项a1=1/2,公比q=1/2的等比数列,设bn+2=3log1/2an,数列{Cn}满足Cn=an*bn.(1)求证:{bn}是等差数列;(2)求数列{Cn}的前n项和Sn;(3)若Cn《2m2+3m一4对一切正整数n都恒成立,求实数m的取值范围.
己知数列{an}是首项a1=1/2,公比q=1/2的等比数列,设bn+2=3log1/2an,数列{Cn}满足Cn=an*bn.(1)...己知数列{an}是首项a1=1/2,公比q=1/2的等比数列,设bn+2=3log1/2an,数列{Cn}满足Cn=an*bn.(1)求证:{b
(1)an=(1/2)^n 3log1/2an=3 bn=3n-2
(2)sn=(1/2)*1+(1/2)^2*4+(1/2)^3*7+...+(1/2)^n*(3n-2)
2sn=1+(1/2)^1*4+(1/2)^2*7+...+(1/2)^(n-1)*(3n-2)
(2-1)sn=1-3[(1/2)^1+(1/2)^2+...+(1/2)^(n-1)]-(1/2)^n(3n-2)
=(8-3n)(1/2)^n-2
(3)(1/2)^n*(3n-2)>=(1/2)^(n+1)*(3n+1)且(1/2)^n*(3n-2)>=(1/2)^(n-1)*(3n-5)
得(Cn)max=C2=1
只需使2m^2+3m-4>=1
解得m=1
ey Dormancy,
8张 2评