Question

What does `cos(arctan(2))` equal?

Answer 1

`cos(arctan(2))=1/sqrt5=sqrt5/5`

Explanation:

arctan(2) is an angle whose tangent function`=2/1`

this means that the angle has opposite side of `2` and adjacent side of `1`

the hypotenuse measures `sqrt5`

cosine of the angle=adjacent side/hypotenuse`=1/sqrt5=sqrt5/5`

God bless America!