1. The problem statement, all variables and given/known data Find the derivative of the function. Simplify if possible. y = arctan (x + sqrt(1+x^2)) 2. Relevant equations I know there's something like... y = arctan(x) = ( x = tan(y) ) I'm not sure how to manipulate it... 3. The attempt at a solution I'm not really sure how to start, any help would be greatly appreciated. Thanks!