Limit of ((x^3 + (4x^2)y)/(x^2+2y^2)) as (x,y)->(0,0)

[adron]

Homework Statement

Find the limit of ((x^3 + (4x^2)y)/(x^2+2y^2)) as (x,y) -> (0,0)

Homework Equations

The Attempt at a Solution

I am guessing the limit is equal to 0, and I know I have to use

0 < sqrt(x^2 + y^2) < delta where |f(x,y) - L| < epsilon

I just have no idea what to do next
I don't want anyone to give me the answer, just a point in the right direction

Sorry about the formatting, I'm quite lost when it comes to Latex.

 

[Dick]

Don't worry about the formatting. We can all read that. You used parentheses and everything. Express it in polar coordinates.

 

[adron]

Sorry it's been a while since I did anything to do with polar, how do I do that?

 

[Dick]

x=r*cos(theta), y=r*sin(theta). You get an r^3 in the numerator and an r^2 in the denominator, yes? Cancel the r^2. Now the limit is r->0.