Find $\lim_{x\rightarrow 0}\exp(-1/(x^2+y^2))$.
I've tried multiplying the power out by the conjugate, which gives me a power of $y^2-x^2/x^4-y^4$, but I still can't figure out how to whittle this down. The most confusing thing to me is that the answer is supposedly $0$. How can $e^\text{anything}$ limit to zero?
EDIT: I should add: I understand the general concept of what the graph looks like, and as the exponent shrinks, the number stretches towards infinity in the x direction. The issue is that I don't know how to actually formally solve this question other than a verbal explanation.
Hint: Think in terms of polar coordinates. $x^2+y^2=r^2$, and use the hint given in the comment by Regret.