1. The problem statement, all variables and given/known data Simplify ##d(log(x^2 + y^2) − z^3)## 2. Relevant equations the derivative? 3. The attempt at a solution The instruction says to simplify. In a similar problem I ended up using the d(a(b-c))= da d(b-c). I am not sure how to deal with the log and only found formulas for ln. Could I just substitute the whole log term with another variable?