Isoptic
From Encyclopedia of Mathematics
The printable version is no longer supported and may have rendering errors. Please update your browser bookmarks and please use the default browser print function instead.
2020 Mathematics Subject Classification: Primary: 52A10 [MSN][ZBL]
The locus of intersections of tangents to a given curve meeting at a fixed angle; when the fixed angle is a right angle, the locus is an orthoptic.
The isoptic of a parabola is a hyperbola; the isoptic of an epicycloid is an epitrochoid; the isoptic of a hypocycloid is a hypotrochoid; the isoptic of a sinusoidal spiral is again a sinusoidal spiral; and the isoptic of a cycloid is again a cycloid.
References
- J.D. Lawrence, "A catalog of special plane curves" , Dover (1972) ISBN 0-486-60288-5 Zbl 0257.50002
How to Cite This Entry:
Isoptic. Encyclopedia of Mathematics. URL: http://encyclopediaofmath.org/index.php?title=Isoptic&oldid=54751
Isoptic. Encyclopedia of Mathematics. URL: http://encyclopediaofmath.org/index.php?title=Isoptic&oldid=54751