The nonsingular inflections of a curve are its nonsingular intersections with the Hessian.
Hessian Covariant
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References
Coolidge, J. L. A Treatise on Algebraic Plane Curves. New York: Dover, pp. 79, 95-98, and 151-161, 1959.Referenced on Wolfram|Alpha
Hessian CovariantCite this as:
Weisstein, Eric W. "Hessian Covariant." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/HessianCovariant.html