We investigate properties of Poncelet $N$-gon families inscribed in a parabola and circumscribing a focus-centered circle. These can be regarded as the polar images of a bicentric family with respect to the circumcircle, such that the bicentric incircle contains the circumcenter. We derive closure conditions for several $N$ and describe curious Euclidean properties such as straight line, circular, and point, loci, as well as a (perhaps new) conserved quantity.
翻译:我们调查Poncelet $N$-gon家庭在抛物线中注册的特性,并限制以焦点为中心的圆圈,这些可以被视为两中心家庭在环圈上的极性图象,因此双中心环圈含有环球。我们为几美元得出关闭条件,描述奇特的欧几里德属性,如直线、圆形和点、地皮,以及(或许是新的)节能数量。