在

中,角

的对边分别为

,且

成等差数列。
(1) 若

,

,求

的值;
(2)求

的取值范围。
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相关习题
科目:高中数学
来源:不详
题型:解答题
(本小题满分16分)
高 已知数列

的前

项和为

,且满足

,

,其中常数

.
(1)证明:数列

为等比数列;
(2)若

,求数列

的通项公式;
(3)对于(2)中数列

,若数列

满足

(

),在

与

之间插入

(

)个2,得到一个新的数列

,试问:是否存在正整数
m,使得数列

的前
m项的和

?如果存在,求出
m的值;如果不存在,说明理由.
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科目:高中数学
来源:不详
题型:解答题
若

,且

,

(1)令

写出

的值,观察并归纳出这个数列的通项公式

;
(2)求证:

。
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科目:高中数学
来源:不详
题型:解答题
.

(本小题满分13分)
在等比数列

中,

已知

,

.
(Ⅰ)求数列

的通项公式;
(Ⅱ)若

,求数列

的前


项和

.
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科目:高中数学
来源:不详
题型:解答题
本题满分13分) 已知等差数列

的首项

,公差

.且

分别是等比数列

的

. (1)求数列

与

的通项公式;
(2)设数列

对任意自然数

均有:

成立.求

的值。
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科目:高中数学
来源:不详
题型:解答题
[文]若数列

的通项公式

,记

.
(1)计算

,

,

的值;
(2)由(1)推测

的表达式;
(3)证明(2)中你的结论.
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