Let $\displaystyle f(x,y) $be defined as follows:

$\displaystyle f(x,y) = 0$ for all (x,y) unless $\displaystyle x^4<y<x^2$

$\displaystyle f(x,y) = 1$ for all (x,y) where $\displaystyle x^4<y<x^2$

Show that $\displaystyle f(x,y)-->0$as $\displaystyle (x,y)-->(0,0)$ on any straight line through (0,0)

Determine if $\displaystyle lim f(x,y)$ exist as $\displaystyle (x,y)-->(0,0)$

just need some explaination on this question