Задание
Преобразуйте в произведение \(\cos{\frac{4\pi}{15}}-\cos{\frac{2\pi}{5}}.\)
- \(\sqrt{3}\sin\frac{\pi}{15}\)
- \(\sin\frac{\pi}{15}\)
- \(\sqrt{3}\cos\frac{\pi}{15}\)
- \(\cos\frac{\pi}{15}\)