Find the equation of the tangent line to the graph of x^2 - xy + y^2 = 19 (where y=y(x)) at (3,-2).
The Attempt at a Solution
So, this is what I did:
d/dx(x^2-xy+y^2) = (19)d/dx
And I am stuck, the answer to this question is:
and I don't know how to get the slope.