Yeah, but the thing is, I tried applying the product rule, and my results were different, I answer did not match with the answer key, so somewhere within the product rule, I screwed up somewhere, so how do you take d/dx(-xy)?
I am pretty sure I got the x^2 and the y^2 part right.
I am just having trouble taking the deriv of the bolded part:
x^2-xy+y^2=19
Do I apply the product rule for the d/dx(-xy)?
Homework Statement
Find the equation of the tangent line to the graph of x^2 - xy + y^2 = 19 (where y=y(x)) at (3,-2).
Homework Equations
The Attempt at a Solution
So, this is what I did:
d/dx(x^2-xy+y^2) = (19)d/dx
2x*dx/dx-dy/dx+dy/dx+2y(dy/dx)=0
2x+2y(dy/dx)=0
And I...