Ответ:
Получаем углы: \(\beta=\frac{\pi}{6}\), \(-\beta=-\frac{\pi}{6}\), \(\frac{\pi}{2}+\frac{\pi}{6}=\frac{2\pi}{3}\), \(\frac{\pi}{2}-\frac{\pi}{6}=\frac{\pi}{3}\), \(\pi+\frac{\pi}{6}=\frac{7\pi}{6}\).
Используем формулы: \(\sin(-\beta)=-\sin\beta\), \(\cos(-\beta)=\cos\beta\); \(\sin(\frac{\pi}{2}+\beta)=\cos\beta\), \(\cos(\frac{\pi}{2}+\beta)=-\sin\beta\); \(\sin(\frac{\pi}{2}-\beta)=\cos\beta\), \(\cos(\frac{\pi}{2}-\beta)=\sin\beta\); \(\sin(\pi+\beta)=-\sin\beta\), \(\cos(\pi+\beta)=-\cos\beta\).
| Угол в радианах | Формула для синуса | Формула для косинуса | Синус | Косинус |
|---|---|---|---|---|
| \(\frac{\pi}{6}\) | \(\sin\beta\) | \(\cos\beta\) | \(\frac{1}{2}\) | \(\frac{\sqrt{3}}{2}\) |
| \(-\frac{\pi}{6}\) | \(\sin(-\beta)=-\sin\beta\) | \(\cos(-\beta)=\cos\beta\) | \(-\frac{1}{2}\) | \(\frac{\sqrt{3}}{2}\) |
| \(\frac{2\pi}{3}\) | \(\sin(\frac{\pi}{2}+\beta)=\cos\beta\) | \(\cos(\frac{\pi}{2}+\beta)=-\sin\beta\) | \(\frac{\sqrt{3}}{2}\) | \(-\frac{1}{2}\) |
| \(\frac{\pi}{3}\) | \(\sin(\frac{\pi}{2}-\beta)=\cos\beta\) | \(\cos(\frac{\pi}{2}-\beta)=\sin\beta\) | \(\frac{\sqrt{3}}{2}\) | \(\frac{1}{2}\) |
| \(\frac{7\pi}{6}\) | \(\sin(\pi+\beta)=-\sin\beta\) | \(\cos(\pi+\beta)=-\cos\beta\) | \(-\frac{1}{2}\) | \(-\frac{\sqrt{3}}{2}\) |
