问题
填空题
求值:sin330°+cos
|
答案
原式=sin(360°-30°)+cos(2π-
)-tan(180°+45°)+cosπ+sin(π+π 3
)+tanπ 3 π 3
=sin(-30°)+cos(-
)-tan(45°)+cosπ-sin(π 3
)+tanπ 3 π 3
=-
+1 2
-1+(-1)-1 2
+3 2 3
=-2+3 2
故答案为:-2+3 2
求值:sin330°+cos
|
原式=sin(360°-30°)+cos(2π-
)-tan(180°+45°)+cosπ+sin(π+π 3
)+tanπ 3 π 3
=sin(-30°)+cos(-
)-tan(45°)+cosπ-sin(π 3
)+tanπ 3 π 3
=-
+1 2
-1+(-1)-1 2
+3 2 3
=-2+3 2
故答案为:-2+3 2