1. The problem statement, all variables and given/known data Use the two path test to prove that the following limits do not exist. 2. Relevant equations [tex]\lim_{(x,y)\rightarrow{(0,0)}}\frac{4xy}{3x^2+y^2}[/tex] 3. The attempt at a solution The book that I am using introduces the Two Path Test theoretically but does not show an example of how to do it, so I am a bit lost. Would I set x = y, and x = -y? In some of the more basic problems I was able to set x = 0 and y = 0, and find the limits would differ, proving that there was no limit. But in this case, that's obviously not possible.
I'm getting 1 and -1, thus the limit does not exist. A question that I have that the book does not address: how do I choose the paths? Do you just try what you think will work until you find something, or is there a specific method of choosing?
There's no formula for picking the paths. Just try some until you get a feeling for what's going on. Other easy ones to try are x=0 and y=0.