# Homework Help: Finding The Limit Of A 3D Function

1. Mar 3, 2013

### Baumer8993

1. The problem statement, all variables and given/known data
Find the limit as X, and Y both approach 0 of (X2Y)/(X2 + Y4)

2. Relevant equations
The equation from above.

3. The attempt at a solution
I have been doing the technique of approaching from different lines such as y = x, or x = y,
x = 0, and y = 0. All of them give me a limit of zero, so that will not do. I graphed the function online, and it appears as if the function does have a limit of zero. How would I prove this? I think I need to do something with polar coordinates, but I am not sure how to do that.

2. Mar 3, 2013

### BloodyFrozen

EDIT:
I'd go with SammyS's

3. Mar 3, 2013

### SammyS

Staff Emeritus
Yes. Change to polar coordinates.

$x=r\cos(\theta)$

$y=r\sin(\theta)$

Last edited: Mar 3, 2013