Alhazen's problem

Alhazen's problem, named after the medieval Arab mathematician and physicist Ibn al-Haytham (known as Alhazen), addresses the challenge of determining the position of a point light source based on the angles of incidence and reflection in a concave mirror. Specifically, it involves finding the location of a point source of light (such as a candle) outside a spherical mirror when given the angles at which the light reflects off the mirror's surface.