计算：sin(-1200°)×cos1230°+cos(-1020°)sin(-1050°)+tan1305°
问题描述：
计算：sin(-1200°)×cos1230°+cos(-1020°)sin(-1050°)+tan1305°
答
sin(-1200+360*4)*cos(1230-360*3)+cos(-1020+3*360)*-sin(-1050+360*3)+tan(1305-180*7)
=sin(240)*cos(150)+cos(60)*sin(30)+tan(45)
=[-sin(60)]*[-cos(30)]+cos(60)*sin(30)+tan(45)
=-((根号)3)/2*-((根号)3)/2+1/2*1/2+1
=3/4+1/4+1
=2