1. The problem statement, all variables and given/known data Find the domain and the first derivative of 2[arctan(e^x)] 2. Relevant equations d/dx arctan(x)= 1/(1+x^2) 3. The attempt at a solution I'm not sure about the domain.... For the derivative: d/dx 2[arctan(e^x)] = 2 [1/(1+e^x)^2] (e^x) But my teacher had the same answer excluding the e^x part. Isn't there supposed to be the e^x there since it is the derivative of the inside function?