## Precalculus: Concepts Through Functions, A Unit Circle Approach to Trigonometry (3rd Edition)

The general equation of a conic has the form of $Ax^2+Bxy+Cy^2+Dx+Ey+F=0(1)$ (a) When $B^2-4AC=0$, then a conic defines a parabola. (b) When $B^2-4AC \lt 0$, then a conic defines an ellipse and $A\ne C$ (c) When $B^2-4AC \lt 0$, then a conic defines a circle and $A=C$ (d) When $B^2-4AC \gt 0$, then a conic defines a hyperbola. We have: $B^2-4AC=0$ Therefore, the conic represents a Parabola.