1. The problem statement, all variables and given/known data Given the equation: x - cos^2(x^2 - y^2) = xy - sin^2(x^2 - y^2) Here's a graph of this equation: http://img240.imageshack.us/my.php?image=graphtq8.png What is the exact point on the tangent line? And what is the slope of the tangent line? 3. The attempt at a solution I know since x=0 at the point, I would need to find y when x=0. But this is confusing me a bit since when I plug in 0 I'm left with -cos(-y^2) = -sin^2(-y^2). And I don't really know when to go from there. I also figure im going to need to derive the equation by implicit differentiation to find the slope I assume. I'm just looking for some suggestions.