Los Angeles Math Circle

11/20 -- LAMC High School: Title: Parabola in the Projective Plane -- Yingkun Li

During the past two meetings, we used paper foldings to trisect angles and solve cubic equations in general. This week, we will change our perspective (literally) and look at parabolas in the projective plane. In particular, we will develop enough tools to find the common tangent of two parabolas in homogeneous coordinate, the coordinate system of the projective plane.