| 1. | \( \left [6,\dfrac{2\pi}{3} \right ] ~\) | 2. | \( \left [6,\dfrac{\pi}{3} \right ] ~\) |
| 3. | \( \left [\sqrt{3},\dfrac{\pi}{6} \right ] ~\) | 4. | \( \left [2\sqrt3,\dfrac{\pi}{6} \right ] ~\) |
| 1. | \(\dfrac{2\pi}{3}\) | 2. | \(\dfrac{\pi}{3}\) |
| 3. | \(\dfrac{\pi}{4}\) | 4. | \(\dfrac{3\pi}{4}\) |