can anybody show me how to simplify: cos(arctan x), im not too sure on how to evaluate that, thanks!
Try to construct a triangle with an angle represented by
This implies that our triangle has an opposite of length and an adjacent of length . We can now use this to determine the length of the hypotenuse of this triangle.
Using Pythagoras' Theorem, we see that
Thus,
Since and , we see that
Does this make sense?
--Chris