1. The problem statement, all variables and given/known data This is to help out a 40something calc student -- thank you all in advance for your help 2. Relevant equations If f (y) = ln ln ln x, what is ∂y/∂x? 3. The attempt at a solution I came up with 1/x, which I got by applying ∂y/∂x ln x = 1/x three times, is this right? Thank you again for your help.