Derivative Function Solve for a,b,c Problem

Here's a Mind Teaser for everyone that certainly is teasing me right now..

Let $\displaystyle f$ be the function that is given by $\displaystyle f(x)= ax+b/x2-c$ and that has the following properties:

1. The graph of $\displaystyle f$ is symmetric with respect to the y-axis (meaning f(x)=f(-x)?)

2. Lim x→3 f(x)= -∞

3. $\displaystyle f'(-2)= -4$

a.) Determine the values of a,b, and c.

b.) Write an equation for each vertical and each horizontal asymptote of the graph $\displaystyle f$.

ATTEMPT:

So I determine that $\displaystyle a$ must equal 0 because if the graph is symettric about the y-axis, that means (x) must equal (-x). I solved for a, and got a=-a, where a=0.

Then I get lost. Where would I go from there?