题目内容
(本小题满分12分)
已知向量
,且![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823144605665409.gif)
(Ⅰ)求tanA的值;
(Ⅱ)求函数
R)的值域.
已知向量
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823144605649734.gif)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823144605665409.gif)
(Ⅰ)求tanA的值;
(Ⅱ)求函数
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823144605681763.gif)
tanA=1,![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823144605696485.gif)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823144605696485.gif)
(Ⅰ)由题意得
························· 2分
因为cosA≠0, ···························· 3分
所以tanA="1." ····························· 4分
(Ⅱ)由(Ⅰ)知tanA=1得
······················· 5分
=
························ 6分
=
····················· 7分
因为x
R,所以
.······················ 8分
当
时,f(x)有最大值
,··················· 10分
当sinx=-1时,f(x)有最小值-2,··················· 11分
所以所求函数f(x)的值域是
·················· 13分
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823144605712622.gif)
因为cosA≠0, ···························· 3分
所以tanA="1." ····························· 4分
(Ⅱ)由(Ⅰ)知tanA=1得
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823144605727602.gif)
=
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823144605743520.gif)
=
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823144605759768.gif)
因为x
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823144605774135.gif)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823144605790516.gif)
当
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823144605805350.gif)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823144605821244.gif)
当sinx=-1时,f(x)有最小值-2,··················· 11分
所以所求函数f(x)的值域是
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823144605696485.gif)
![](http://thumb.zyjl.cn/images/loading.gif)
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