# How do you simplify #cos(arctan(x)) #?

##### 2 Answers

#### Explanation:

Let simplify

Let

We need to have an expression for

\0/ Here's our answer !

Continuation of my first answer that was edited by another.

#### Explanation:

Let a = arctan ( x ).

The principal value of

Then

previous answer, two years ago).

Now, the given expression is

It is important that

If the piecewise-wholesome general inverse operator

the negative sign is chosen, when

Example:

So, the value is

My intention, in this approach, is to inform about nuances..

So, I am making a second answer,