How do you find the derivative of #ln(x^2+y^2)#?
There are two possible pathways here: implicit differentiation or partial differentiation.
For implicit differentiation, we have both variables (
Implicitly differetiating, then, we must resort to chain rule, by naming
Now, going to partial differentiation: we keep the chain rule logic, but in the end, we proceed differently, differentiating only one of the two variables, as follows: