问题
填空题
求值:
|
答案
=sin10°-
cos10°3 cos40° 2(
sin10°-1 2
cos10°)3 2 cos40°
=
=2(sin10°cos60°-cos10°sin60°) cos40°
=-22sin(-50°) cos40°
故答案为-2.
求值:
|
=sin10°-
cos10°3 cos40° 2(
sin10°-1 2
cos10°)3 2 cos40°
=
=2(sin10°cos60°-cos10°sin60°) cos40°
=-22sin(-50°) cos40°
故答案为-2.