问题
填空题
sin27°sin33°-cos333°sin57°=______.
答案
sin27°sin33°-cos333°sin57°
=sin27°cos57°-cos27°sin57°
=sin(27°-57°)
=sin(-30°)
=-
.1 2
故答案为:-
.1 2
sin27°sin33°-cos333°sin57°=______.
sin27°sin33°-cos333°sin57°
=sin27°cos57°-cos27°sin57°
=sin(27°-57°)
=sin(-30°)
=-
.1 2
故答案为:-
.1 2