1 . 在直角坐标系
中,以
为始边分别作角
,
,其终边分别与单位圆交于点
,
.
(1)证明:
;
(2)已知
,
为锐角,
,
,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ee31829d0d4d5f779a957d7df8058ab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c3e5af20b2f8c1fba4470f9650989e51.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b5858ee1ce52b251816757257a11c29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d4e4c210b2342523b23a43e0a5fd4f63.png)
(2)已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b5858ee1ce52b251816757257a11c29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e82e61189eee22b8a316b16ead9fed5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ccd1dfdc167165bcad456709247c723.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/800db22e042a298041eda8b0c72abb7c.png)
您最近一年使用:0次
2023-04-04更新
|
172次组卷
|
2卷引用:山东省泰安肥城市2022-2023学年高一下学期期中考试数学试题
解题方法
2 . 写出两角差的余弦公式,并利用单位圆以及向量的数量积证明该公式.
您最近一年使用:0次