# What is the Value of Tan 120 Degrees ?

## Solution :

The value of tan 120 degrees is $$-\sqrt{3}$$.

Proof :

We Know that tan 60 = $$\sqrt{3}$$.

By using formula of tan 2A,

tan 120 = $$2 tan 60\over 1 – tan^2 60$$ = $$2 \times \sqrt{3}\over 1 – 3$$

$$\implies$$  tan 120 = $$-\sqrt{3}$$