Inside a circle of center O and radius r, take two points A and B symmetrical about O. We consider a variable point P on the circle and draw the chord PP′⊥AP. Let C is the symmetric of B about PP′ (PP′ is the axis of symmetry) . Find the locus of point Q \equal{} \overline{PP'}\cap\overline{AC} when we change P in the circle. symmetrygeometrygeometric transformationreflectiontrapezoidconicsellipse