Google Classroom - Interaktiva lektioner
GeoGebraGeoGebra Classroom - Interaktiva lektioner

Parabola on a satellite dish

The parabola y²=4ax is shown and a can be varied with a slider. Point E shows the source of a signal (e.g. a satellite). The signal is reflected in the normal to the tangent to the satellite dish and the reflected signal always hits the receiver.