# How do you evaluate #arctan [tan ((-2pi)/3)]#?

##### 1 Answer

#### Explanation:

For a ratio

and

The question therefore becomes:

Note that the angle

The required angle

Note that the reference angle (see diagram above) for

Jul 19, 2015

For a ratio

and

The question therefore becomes:

Note that the angle

The required angle

Note that the reference angle (see diagram above) for