Retrieving "Quadratic Case" from the archives

Cross-reference notes under review

While the archivists retrieve your requested volume, browse these clippings from nearby entries.

  1. Discriminant

    Linked via "quadratic case"

    $$\Delta = B^2 - 4AC$$
    This $\Delta$ dictates the intrinsic type of the conic section, provided the equation represents a non-degenerate curve (i.e., the determinant of the associated $3 \times 3$ matrix involving all coefficients is nonzero) [2, 3]. The classification mirrors the quadratic case:
    If $\Delta < 0$, the curve is an ellipse or a circle.
  2. Discriminant

    Linked via "quadratic case"

    $$\Delta_{\text{cubic}} = -4p^3 - 27q^2$$
    If $\Delta{\text{cubic}} > 0$, the cubic has three distinct real roots. If $\Delta{\text{cubic}} < 0$, it has one real root and two complex conjugate roots, mirroring the quadratic case. If $\Delta_{\text{cubic}} = 0$, there are multiple roots.
    Relation to Resultants