A.\( - \dfrac{1}{6}\cos 6x - \dfrac{1}{2}\cos 2x + 6\)
B.\( - \dfrac{1}{6}\cos 6x - \dfrac{3}{2}\cos 2x + 6\)
C.\( - \dfrac{1}{6}\cos 6x - \dfrac{{\sqrt 3 }}{2}\cos 2x + 8\)
D.\( - \dfrac{1}{6}\cos 6x - \dfrac{5}{2}\sin 2x + 8\)

A.
B.
C.
D.

A.4
B.5
C.0
D.6

A.2
B.4
C.0
D.8

A.\(A = B\)
B.\(A > B\)
C.\(A < B\)
D.không so sánh được

A.0
B.9
C.3
D.1

A.21
B.27
C.23
D.24

A.20
B.19
C.23
D.15

A.0
B.9
C.13
D.12

A.0
B.2
C.3
D.1