Find the limits, if they exist, or type DNE for any which do not exist.

$$\displaystyle \lim_{(x, y) \rightarrow (0, 0)} \frac{2 x^2}{ 3 x^2+ y^2}$$ 1) Along the $x$-axis:
2) Along the $y$-axis:
3) Along the line $y=mx$ :
4) The limit is: