题目内容
计算•cos30°.
【答案】分析:首先把特殊角的三角函数值代入,然后进行运算即可求解.
解答:解:原式=(
×
-
×
)×
=0.
点评:本题考查了特殊角的三角函数值,正确记忆特殊角的三角函数值是关键.
解答:解:原式=(
![](http://thumb.1010pic.com/pic6/res/czsx/web/STSource/20131101185545823639891/SYS201311011855458236398022_DA/0.png)
![](http://thumb.1010pic.com/pic6/res/czsx/web/STSource/20131101185545823639891/SYS201311011855458236398022_DA/1.png)
![](http://thumb.1010pic.com/pic6/res/czsx/web/STSource/20131101185545823639891/SYS201311011855458236398022_DA/2.png)
![](http://thumb.1010pic.com/pic6/res/czsx/web/STSource/20131101185545823639891/SYS201311011855458236398022_DA/3.png)
![](http://thumb.1010pic.com/pic6/res/czsx/web/STSource/20131101185545823639891/SYS201311011855458236398022_DA/4.png)
点评:本题考查了特殊角的三角函数值,正确记忆特殊角的三角函数值是关键.
![](http://thumb2018.1010pic.com/images/loading.gif)
练习册系列答案
相关题目
计算cos30°+
tan60°的值是( )
| ||
3 |
A、
| ||||
B、
| ||||
C、
| ||||
D、
|