multivariable limit

oxxiissiixxo

New member
Joined
Sep 29, 2009
Messages
5
I'm taking multi-variable after having a while off from school, so forgive me if these are simple ones that I just don't "see"

1. The problem statement, all variables and given/known data
lim (x, y) --> 0, 0 LaTeX Code: \\frac{x^2 y^2 e^y}{x^4+4y^2}

and

lim (x, y) --> (1, 1) LaTeX Code: \\frac{x-y}{x^3-y}

2. Relevant equations



3. The attempt at a solution

The bottom one I feel doesn't exist because as x->0+, the ^3 is making it larger, where as when x->0-, the ^3 is making it smaller. I know this is poor logic; it's just a gut feeling about it. substituting y=mx or similar didn't get me anywhere. Plugging obviously doesn't work. I don't see anyway to simplify, but maybe there is a way. I also don't think polar coordinates will work for either.

I really think I only need a hint to the method of solution, so don't go solving the whole thing for me.
 
Top