问题
填空题
求值:sin73°cos13°-sin13°cos73°=______.
答案
sin73°cos13°-sin13°cos73°
=sin73°cos13°-cos73°sin13°
=sin(73°-13°)
=sin60°
=
.3 2
故答案为:3 2
求值:sin73°cos13°-sin13°cos73°=______.
sin73°cos13°-sin13°cos73°
=sin73°cos13°-cos73°sin13°
=sin(73°-13°)
=sin60°
=
.3 2
故答案为:3 2