Question

What does `cos(arctan(pi/4))` equal?

Answer 1

`=1/sqrt(1+(pi/4)^2`

Explanation:

`cos(arctan(pi/4))`
`=1/sec(arctan(pi/4))`
`=1/sqrt(1+tan^2(arctan(pi/4))`
`=1/sqrt(1+(tan(arctan(pi/4))^2`
`=1/sqrt(1+(pi/4)^2`