Envelope of unit circles Centred on an Astroid

Envelope(s) of unit circles centered on an astroid
Move the point A along the astroid. [br]Note:[br]1. the position of the points of contact of the circles with the two components of the envelope[br]2. The points where a jump occurs[br]3. The correspondence between the cusps of the astroid and the cusps of the envelope(s)

Information: Envelope of unit circles Centred on an Astroid