1) x^2 + xy - y^2 = 4
x^2 + x*y(x) - y(x)^2 = 4
I understand this much: 2x + ____ + 2y*(dy/dx) = 0
But I don't understand how to differentiate the middle portion properly. I'm assuming it's just the product rule, but doing it didn't lead me to the right answer.
2) x^4(x + y) = y^2(3x - y)
Product rule again?