求值sin2120°+cos180°+tan45°-cos2(-330°)+sin(-210°)-数学

题目简介

求值sin2120°+cos180°+tan45°-cos2(-330°)+sin(-210°)-数学

题目详情

求值sin2120°+cos180°+tan45°-cos2(-330°)+sin(-210°)
题型:解答题难度:中档来源:不详

答案

sin2120°+cos180°+tan45°-cos2-(-330°)+sin(-210°)
=(
3
2
)2-1+1-cos230°-sin210°
=class="stub"3
4
-(
3
2
)2+sin30°=sin30°
=class="stub"1
2

故答案为class="stub"1
2

更多内容推荐