Question

[Pham Trong Bach]

Giải phương trình sin⁡x+ sin2x+ sin3x= cosx+ cos2x+ cos3x

A.  x = 2 π / 3 + k 2 π   h o ặ c x = π / 8 + k   π / 2   ( k ∈ Z )

B.  x = ± 2 π / 3 + 2 π   h o ặ c x = π / 8 + k   π / 2   ( k ∈ Z )

C.  x = ± 2 π / 3 + k 2 π   h o ặ c x = ± π / 8 + k   π / 2   ( k ∈ Z )

D.  x = ± 2 π / 3 + k 2 π   h o ặ c x = π / 8 + k   π / 2   ( k ∈ Z )

Answer 1

[Cao Minh Tâm]