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【332307】2.2 30°,45°,60°角的三角比 基础练习

时间:2025-01-21 12:36:29 作者: 字数:1032字
简介:

2.2 30°45°60°角的三角比

1、若α为锐角,则0 sinα 10 cosα 1

2、已知cosA= <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/197/" title="基础" class="c1" target="_blank">基础</a> <a href="/tags/920/" title="三角" class="c1" target="_blank">三角</a> ,且∠B=90°-∠A,则sinB=

3、计算:  <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/197/" title="基础" class="c1" target="_blank">基础</a> <a href="/tags/920/" title="三角" class="c1" target="_blank">三角</a> sin45°- <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/197/" title="基础" class="c1" target="_blank">基础</a> <a href="/tags/920/" title="三角" class="c1" target="_blank">三角</a> cos600=

4、计算:  <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/197/" title="基础" class="c1" target="_blank">基础</a> <a href="/tags/920/" title="三角" class="c1" target="_blank">三角</a> sin45°- <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/197/" title="基础" class="c1" target="_blank">基础</a> <a href="/tags/920/" title="三角" class="c1" target="_blank">三角</a> tan60°=

5、计算: (sin30°+tan45°)·cos60°=

6、若0<α<900sinα=cos60°,则tanα=

7、在Rt△ABC中,∠C为直角, ∠A=30°,则sinA+sinB=( )
A
1B <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/197/" title="基础" class="c1" target="_blank">基础</a> <a href="/tags/920/" title="三角" class="c1" target="_blank">三角</a> C <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/197/" title="基础" class="c1" target="_blank">基础</a> <a href="/tags/920/" title="三角" class="c1" target="_blank">三角</a> D <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/197/" title="基础" class="c1" target="_blank">基础</a> <a href="/tags/920/" title="三角" class="c1" target="_blank">三角</a>

8、已知sinA=  <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/197/" title="基础" class="c1" target="_blank">基础</a> <a href="/tags/920/" title="三角" class="c1" target="_blank">三角</a> (∠A为锐角),则∠A=____cosA___tanA=____

9、在Rt△ABC中,∠C为直角,AC=4BC=3,则sinA=( )
A
 <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/197/" title="基础" class="c1" target="_blank">基础</a> <a href="/tags/920/" title="三角" class="c1" target="_blank">三角</a> B <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/197/" title="基础" class="c1" target="_blank">基础</a> <a href="/tags/920/" title="三角" class="c1" target="_blank">三角</a> C <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/197/" title="基础" class="c1" target="_blank">基础</a> <a href="/tags/920/" title="三角" class="c1" target="_blank">三角</a> D <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/197/" title="基础" class="c1" target="_blank">基础</a> <a href="/tags/920/" title="三角" class="c1" target="_blank">三角</a>

10、在Rt△ABC中,∠C为直角,sinA= <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/197/" title="基础" class="c1" target="_blank">基础</a> <a href="/tags/920/" title="三角" class="c1" target="_blank">三角</a> ,则cosB的值是( )
A
 <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/197/" title="基础" class="c1" target="_blank">基础</a> <a href="/tags/920/" title="三角" class="c1" target="_blank">三角</a> B <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/197/" title="基础" class="c1" target="_blank">基础</a> <a href="/tags/920/" title="三角" class="c1" target="_blank">三角</a> C1 D <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/197/" title="基础" class="c1" target="_blank">基础</a> <a href="/tags/920/" title="三角" class="c1" target="_blank">三角</a>

11、当锐角A>45°时,sinA的值( )

A.小于 <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/197/" title="基础" class="c1" target="_blank">基础</a> <a href="/tags/920/" title="三角" class="c1" target="_blank">三角</a> B.大于 <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/197/" title="基础" class="c1" target="_blank">基础</a> <a href="/tags/920/" title="三角" class="c1" target="_blank">三角</a> C.小于 <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/197/" title="基础" class="c1" target="_blank">基础</a> <a href="/tags/920/" title="三角" class="c1" target="_blank">三角</a> D.大于 <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/197/" title="基础" class="c1" target="_blank">基础</a> <a href="/tags/920/" title="三角" class="c1" target="_blank">三角</a>



参考答案

1. < < < <2.  <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/197/" title="基础" class="c1" target="_blank">基础</a> <a href="/tags/920/" title="三角" class="c1" target="_blank">三角</a> 3. 3/44. -25. 3/46.  <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/197/" title="基础" class="c1" target="_blank">基础</a> <a href="/tags/920/" title="三角" class="c1" target="_blank">三角</a>

7. B8. 30°  <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/197/" title="基础" class="c1" target="_blank">基础</a> <a href="/tags/920/" title="三角" class="c1" target="_blank">三角</a>  <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/197/" title="基础" class="c1" target="_blank">基础</a> <a href="/tags/920/" title="三角" class="c1" target="_blank">三角</a> 9. C10. D 11. B