求值:(1)sin(-4π3)cos(-23π6)tan25π4;(2)1sin100-3cos100.-数学

题目简介

求值:(1)sin(-4π3)cos(-23π6)tan25π4;(2)1sin100-3cos100.-数学

题目详情

求值:
(1)sin(-
3
)cos(-
23π
6
)tan
25π
4

(2)
1
sin100
-
3
cos100
题型:解答题难度:中档来源:不详

答案

(1)sin(-class="stub"4π
3
)cos(-class="stub"23π
6
)tanclass="stub"25π
4
=sinclass="stub"π
3
cosclass="stub"π
6
(-tanclass="stub"π
4
)=
3
2
×
3
2
×(-1)
=class="stub"3
4

(2)class="stub"1
sin10° 
-
3
cos10° 
=
cos10°-
3
sin10°
sin10°cos10°
=
2(class="stub"1
2
cos10°-
3
2
sin10°)
class="stub"1
2
sin20°
=class="stub"4sin20°
sin20°
=4

更多内容推荐