Chapter 7 - Trigonometry and Periodic Functions - 7.7 Trigonometric Relationships and Identities - Exercises and Problems for Section 7.7 - Exercises and Problems - Page 309: 1

$$-\sqrt{3}$$

To evaluate trigonometric functions without a calculator, it is necessary to use the unit circle. Doing this, we find that the function evaluates to: $$\frac{\sin \left(\frac{2\pi }{3}\right)}{\cos \left(\frac{2\pi }{3}\right)} \\ \frac{\frac{\sqrt{3}}{2}}{\left(-\frac{1}{2}\right)} \\ -\sqrt{3}$$