Hey guys, I'm doing some multivariable calculus atm, and I need some help with the Domains of some multivariable functions... 1) f(x,y) = 3x^2 + 2y The problem I'm having here is I basically forget the definition of domain... would it be for all x and y even though there are two whole quadrants this function doesn't hit? (looking at the x-y plane here..) 2) f x(x,y) = 6x I'm looking at the partial derivative in regards to x here. Would I just assume this is a single variable function and only write the Domain in terms of x? If not, what would I write for the Domain? 3)f y(x,y) = 2 This is the partial derivative in terms of y, I know on the x-y plane it would be defined for all x... is it the same here?