Find an orthogonal change of variables that eliminates the cross product terms in the quadratic form f(x, y) = x2 + 2xy + y2 and express it in terms of the new variables. (b) Use the result in part (a) to identify the conic section (ellipse, parabola or hyperbola) represented by the equation x2 + 2xy + y2 + 3x + y - 1 = 0. Sketch the graph of this conic section.
