phương trình $cos2x+2cos^{2}x-1=0$ có tập nghiệm là:

Question

Cơ bản

4 câu trả lời

Answer 1

$\left \{ \frac{\pi }{4}+k\pi ,k\in \mathbb{Z} \right \}$

Answer 2

$\left \{ \frac{\pi }{4}+k\frac{\pi }{2} ,k\in \mathbb{Z} \right \}$

Answer 3

$\left \{ \frac{\pi }{4}+k2\pi,k\in \mathbb{Z} \right \}$

Answer 4

$\left \{ k\pi ,k\in \mathbb{Z} \right \}$