I know this might sound like a very, very peculiar question, with a very, very peculiar description. Anyway, I am currently going for the fourth and last year of my curriculum in Physics school and I want to be completely honest with you before I even ask: I do have a noticeable bunch of courses...
OK, our Calc professor gave us a paper with some limits to calculate, but I'm not quite sure about them...Here are some examples:
a)lim (5x^5+3y^5)/(x^2y^2+1)
x->0
y->0
Since the obvious replacement is too suspicious, I thought about looking if it exists by using the y=mx line...