where x(t) is given by:
and y(t) similarly is given by:
You then derive the expression with respect to t and you should get:
or if you want it only in terms of t you can insert the function x(t), y(t), x'(t), and y'(t) in their respective places to get:
and plug in t = 2 to get:
I believe that is right, but that answer certainly is not pretty.