已知函数f(x)=cosx?sin(x+π3)-3cos2x+34,x∈R.(Ⅰ)求f(x)的最小正周期;(Ⅱ)求f(x)在闭区

2025-06-28 04:07:51
推荐回答(1个)
回答1:

(Ⅰ)由题意得,f(x)=cosx?(

1
2
sinx+
3
2
cosx)?
3
cos2x+
3
4

=
1
2
sinx?cosx?
3
2
cos2x+
3
4
          
=
1
4
sin2x?
3
4
(1+cos2x)+
3
4

=