已知向量
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131025123758580256490/SYS201310251237585802564016_ST/0.png)
.记f(x)=
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131025123758580256490/SYS201310251237585802564016_ST/1.png)
•
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131025123758580256490/SYS201310251237585802564016_ST/2.png)
(I)若
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131025123758580256490/SYS201310251237585802564016_ST/3.png)
,求
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131025123758580256490/SYS201310251237585802564016_ST/4.png)
的值;
(Ⅱ)在△ABC中,角A、B、C的对边分别是a、b、c,且满足(2a-c)cosB=bcosC,若
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131025123758580256490/SYS201310251237585802564016_ST/5.png)
,试判断△ABC的形状.
考点分析:
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