确定下列各角的正弦、余弦、正切值的符号:
(1)
;
(2)
;
(3)
;
(4)
.
(1)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e99be4eebc39a11e138b0e5d1cd9dec7.png)
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c9a71b2b63608564ab8691bc97473ad.png)
(3)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d82a36e5d5cd1b6b26433fdda2bc2af1.png)
(4)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2ad0762df2e86af61058d1081289881b.png)
更新时间:2023-09-27 00:06:13
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【知识点】 已知角或角的范围确定三角函数式的符号解读