1. The problem statement, all variables and given/known data The graph of the tilted ellipse x^2 -xy +y^2 =3 is shown to the right. What are the dimensions and the location of the box containing the ellipse? Note the sides of the box are vertical and horizontal and also are tangent to the elipse. (The image is simply a tilted elipse inside a box which looks to be a square and is tangent to the elipse at four places two at the top right and two at the bottom left. 2. Relevant equations 3. The attempt at a solution My first thought is to find where the derivative equals 0. The derivative I found through implicit differentiation is (2x-y)/(x-2y) = dy/dx I set this to zero but got an equation with two variables? I'm not sure what to do from here.