这道题求解答啊谢谢

2025-01-05 15:39:57
推荐回答(2个)
回答1:

如图

回答2:

f(x)=sin²x-1/2=(1-cos2x)/2-1/2=-1/2 cos2x
g(X)=-2× 1/2 cos【2(x-π/6)】=-cos(2x-π/3)
g(5π/6)=1/2
选B