# How do you evaluate #arccos(cos(5pi/4))#?

##### 2 Answers

Jul 29, 2015

Evaluate

Ans:

#### Explanation:

Jul 29, 2015

#### Explanation:

(It can also be thought of as simply a number between

The restriction to angles between

The angle we want is

We know that

and the Quadrant II angle with cosine equal to

is