
06495941
j
2015f.00735
Berendonk, Stephan
Stretched circles are conic sections, a geometric proof.
Coll. Math. J. 45, No. 4, 316317 (2014).
2014
Mathematical Association of America (MAA), Washington, D.C.
EN
G75
G45
conic sections
ellipses
doi:10.4169/college.math.j.45.4.316
Summary: We give a geometric proof for the fact that a conic section, if it is a closed curve, satisfies the equation of an ellipse.