Question

The graph of the equation 2x2 + xy + y2 = 4 is the tilted ellipse pictured below; i.e. the points (x,y) in the plane that satisfy the equation yield the pictured ellipse.

Answer 1

This is NOT the graph of a function y=f(x). However, if you solve the original equation for y in terms of x, you can break the graph into two pieces, each of which is the graph of a function.

The real solution are : x= -4/sqroot7, y= 2/sqroot 7

                                         x= 4/sqroot7, y= -2/sqroot 7

integer solution are: (-1,2) , (1,-2), (1,1)