Find an equation of the tangent line to the graph at the given point.

Question

3(x2 + y2)2 = 100(x2 − y2), (4, -2)

Answer 1

6 (x^2+y^2)(2x+2ydy/dx)=100(2x-2ydy/dx)
find dy/dx at (4,-2)

6(16+4)(8-4dy/dx)=100(8+4dy/dx)

solve for dy/dx which is m in y = m x + b

then use the given point in the given equation to find b