已知
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823213821661481.png)
是首項為1的等比數(shù)列,
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823213821692328.png)
是
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823213821661481.png)
的前n項和,且
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823213821739486.png)
,則數(shù)列
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823213821755613.png)
的前5項和為( )
首項為1的等比數(shù)列且
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823213821739486.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823213821895397.png)
否則9=1
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823213821989994.png)
,
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/201408232138220041059.png)
,
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823213821755613.png)
是首項為1,公比是
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823213822036338.png)
的等比數(shù)列,
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/201408232138220511033.png)
=
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823213821802447.png)
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科目:高中數(shù)學
來源:不詳
題型:解答題
( 14分)在數(shù)列
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823215012118456.png)
,
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823215012133471.png)
中,
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823215012149412.png)
,
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823215012180419.png)
且
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823215012196348.png)
,
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823215012211365.png)
,
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823215012430400.png)
成等差數(shù)列,
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823215012211365.png)
,
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823215012430400.png)
,
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823215012477415.png)
成等比數(shù)列(
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823215012508519.png)
)
(1)求
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823215012523344.png)
,
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823215012539352.png)
,
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823215012570334.png)
及
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823215012586348.png)
,
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823215012617360.png)
,
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823215012633343.png)
,
(2)由(1)猜測數(shù)列
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823215012118456.png)
,
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823215012133471.png)
的通項公式,并用數(shù)學歸納法證明你的結(jié)論;
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科目:高中數(shù)學
來源:不詳
題型:填空題
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823213914686456.png)
為等比數(shù)列,若
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823213914748856.png)
,則數(shù)列
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823213914686456.png)
的通項
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823213914811348.png)
=_______.
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來源:不詳
題型:解答題
已知正項等比數(shù)列
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212805367920.png)
若存在兩項
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212805382382.png)
、
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212805398348.png)
使得
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212805413641.png)
,且有
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212805445580.png)
≥
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212805523543.png)
對上述
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212805538435.png)
恒成立,求x的取值范圍.
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來源:不詳
題型:單選題
已知等比數(shù)列
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823211751989481.png)
的公比為正數(shù),且
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823211752005633.png)
,
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823211752020378.png)
,則
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823211752036325.png)
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