A function is said to have a vertical asymptote wherever the limit on the left or right (or both) is either positive or negative infinity.
For example, the function $f(x)= \frac{x^2-4}{(x-3)^2}$ has a vertical asymptote at $x=3$.

For each of the following limits, enter either 'P' for positive infinity, 'N' for negative infinity, or 'D' when the limit simply does not exist.
$\displaystyle{ \lim_{x\to 3^-} \frac{x^2-4}{(x-3)^2} = }$
$\displaystyle{ \lim_{x\to 3^+} \frac{x^2-4}{(x-3)^2} = }$
$\displaystyle{ \lim_{x\to 3} \frac{x^2-4}{(x-3)^2} = }$

Your overall score for this problem is