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计算不太明白...求值sin(-1320°)*cos1110°+cos(-1020°)sin750°+tan(-405°

来源:学生作业帮 编辑:作业帮 分类:综合作业 时间:2024/05/20 01:37:08
计算
不太明白...
求值sin(-1320°)*cos1110°+cos(-1020°)sin750°+tan(-405°)
求值sin25π/6+cos25π/3+tan25π/4+sin7π/3*cos13π/6-cos5π/3
sin(-1320°)*cos1110°+cos(-1020°)sin750°+tan(-405°)
=sin120°cos30°+cos60°sin30°-tan45°
=sin60°cos30°+cos60°sin30°-tan45°
=3/4+1/4-1
=0
sin25π/6+cos25π/3+tan25π/4+sin7π/3*cos13π/6-cos5π/3
=sinπ/6+cosπ/3+tanπ/4+sinπ/3cosπ/6-cosπ/3
=1/2+1/2+1+√3/2(1/2)-1/2
=3/2+√3/4