Ellipse Representation

This diagram represents an ellipse in the plane with coordinates (x1, x2), where x1 and x2 are the variables corresponding to the x-axis and y-axis respectively, and r is the radius of the ellipse. The semi-major axis is along the x2 axis and its length is r, while the semi-minor axis is along the x1 axis and its length is r*sqrt(2). The center of the ellipse is at the origin (0,0).