Parallel Rays and the Focus

A parabola turns parallel rays into a focused point, and rays emitted from the focus leave parallel. Toggle between the two directions.

Teaching Notes

Core Idea

Parabolic mirrors convert parallel rays into one focus point, and reverse that path too.

Try This

Switch modes and observe that each path is reversible when reflected over the same surface.

Teacher Prompt

Connect this to flashlights, headlights, and satellite dishes.

Vocabulary

Directrix: fixed line in parabola definition.
Focus: fixed point paired with directrix.
Axis of symmetry: vertical line through focus.