Point

x^2 + y^2 = 0		 Circle

x^2 + y^2 = r^2
Ellipse

x^2 / a^2 + y^2 / b^2 = 1		 Ellipse

x^2 / b^2 + y^2 / a^2 = 1		 Hyperbola

x^2 / a^2 - y^2 / b^2 = 1
Parabola

4px = y^2		 Parabola

4py = x^2		 Hyperbola

y^2 / a^2 - x^2 / b^2 = 1
                                         فرانکو