Here's how you tell just by looking at the equation, assuming there are no xy terms: Circle -- 2nd degree polynomial equation having both x² and y² terms with the same COEFFICIENT when on the same side of the equation. Parabola -- 2nd degree polynomial equation having only an x² term or a y² term but not both. Hyperbola -- 2nd degree polynomial equation having both x² and y² terms with OPPOSITE SIGNS when on the same side of the equation. Ellipse -- 2nd degree polynomial equation having both x² and y² terms with DIFFERENT COEFFICIENTS BUT BOTH WITH THE SAME SIGN when on the same side of the equation. ------------------------------------ x²-4y²-4x-24y=48 That's a polynomial equation having both x² and y² terms with OPPOSITE SIGNS when on the same side of the equation. So it's a HYPERBOLA. Edwin