سوال :
جوابهای معادله مثلثاتی \(sin(x + \frac{\pi}{6}) + cos(x + \frac{\pi}{3}) = cos 2x\) کدام است؟
- 1.\( x = \frac{2k\pi}{3}, k \in Z \)
- 2.\( x = \frac{k\pi}{3}, k \in Z \)
- 3.\( x = 2k\pi \pm \frac{\pi}{3}, k \in Z \)
- 4.\( x = k\pi \pm \frac{\pi}{3}, k \in Z \)
