First, watch your notation. You can't write a trig function without an angle. You must write something likeI know sin=3 and cos=-2 but that is it.
Second, neither value is possible. Sine or cosine of any angle will be between -1 and 1 inclusive. If you're using the point (x, y) to figure out sine and cosine, you need these definitions:
In other words, you forgot to divide each by r. (r is easy to find, it's just ).
Please clarify your question(s).