An isoptic curve formed from the locus of tangents meeting at right angles. The orthoptic of a parabola is its conic section directrix. The orthoptic of a central conic was investigated by Monge and is a circle concentric with the conic section. The orthoptic of an astroid is a circle.
Orthoptic Curve
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References
Lawrence, J. D. A Catalog of Special Plane Curves. New York: Dover, pp. 58 and 207, 1972.Referenced on Wolfram|Alpha
Orthoptic CurveCite this as:
Weisstein, Eric W. "Orthoptic Curve." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/OrthopticCurve.html