How do you differentiate y=(x-y)^2/(x+y)y=(xy)2x+y?

1 Answer
Sep 25, 2017

Given: y=(x-y)^2/(x+y); x!=-yy=(xy)2x+y;xy

Multiply both sides by x+yx+y:

xy+y^2 = (x-y)^2xy+y2=(xy)2

Expand the square:

xy+y^2 = x^2 -2xy+y^2xy+y2=x22xy+y2

Combine like terms:

3xy = x^23xy=x2

Divide both sides by 3x3x:

y = 1/3xy=13x

dy/dx = 1/3dydx=13

If you do not believe the result, here is a graph of y=(x-y)^2/(x+y)y=(xy)2x+y to prove that is merely a line with a slope of 1/313:

![www.desmos.com/calculator](useruploads.socratic.org)