Calculus AB AP test practice problem

This is a problem from the 1990 Calculus AB test.

Let f be the function that is given by f(x)= (ax+b)/(x^2-c) and that has the following properties:

i) The graph of f is symmetric with respect to the y axis

ii) lim (as x--> 2+)= +infinity

iii) f ' (1)= -2

a) determine the values of a, b, and c

b) write an eqn. for each vertical and horizontal asymptote

c) sketch the graph of f

I just need help with part a, after that i can figure out parts b and c on my own! i keep trying different things but im stuck. thank you!!