在△ABC中角A,B,C所对的边长分别为a,b,c,且
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101225157519442834/SYS201311012251575194428020_ST/0.png)
.
(Ⅰ)求角A的大小;
(Ⅱ)若a=2,求△ABC周长的最大值及相应的b,c值.
考点分析:
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已知函数
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的值;
(Ⅱ)求函数f(x)的单调递增区间及其图象的对称轴方程.
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已知|
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,
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.
(Ⅰ)若
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101225157519442834/SYS201311012251575194428017_ST/2.png)
∥
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101225157519442834/SYS201311012251575194428017_ST/3.png)
,求
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101225157519442834/SYS201311012251575194428017_ST/4.png)
;
(Ⅱ)若
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101225157519442834/SYS201311012251575194428017_ST/5.png)
、
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101225157519442834/SYS201311012251575194428017_ST/6.png)
的夹角为60°,求
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101225157519442834/SYS201311012251575194428017_ST/7.png)
;
(Ⅲ)若
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101225157519442834/SYS201311012251575194428017_ST/8.png)
与
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101225157519442834/SYS201311012251575194428017_ST/9.png)
垂直,求当k为何值时,
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101225157519442834/SYS201311012251575194428017_ST/10.png)
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101225157519442834/SYS201311012251575194428017_ST/11.png)
?
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已知非零向量
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的夹角为60°,且
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101225157519442834/SYS201311012251575194428016_ST/1.png)
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满足
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,则
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的最大值为
.
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有一道解三角形的题,因为纸张破损,在划横线地方有一个已知条件看不清.具体如下:在△ABC中角A,B,C所对的边长分别为a,b,c,已知角B=45°,
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101225157519442834/SYS201311012251575194428015_ST/0.png)
,
,求角A.若已知正确答案为A=60°,且必须使用所有已知条件才能解得,请你写出一个符合要求的已知条件.
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