9.1 General Form of a Conic
The regular form of a conic is: Ax2 + Bxy + Cy2 + Dx + Ey + F = 0. Before you start manipulating the general form of a conic equation you should be able to recognize whether it is a circle, ellipse, parabola or hyperbola. In standard form, the two coefficients to examine are A and C. For circles, the coefficients of x2.