Question

What does `cos(arctan(sin((-3pi)/4)) )` equal?

Answer 1

`sqrt(1/2)`

Explanation:

Operations are from innermost parantheses in the nest.
`sin(-3pi/4)=- sin(pi-pi/4)=-sin(pi/4)=-1/sqrt2`

`arctan(-1/sqrt2)=-arctan(1/sqrt2)=-pi/4`

`cos(-pi/4) = cos(pi/4) = 1/sqrt2`.