Thanks everyone!

I will leave the page as it is until I can think of a way to simplify it without straying into "y=2x+3 becomes y=(x-3)/2" territory.

Thanks Guys!

I found Wolfram uses f-¹(x): http://mathworld.wolfram.com/InverseFunction.html

It would be nice to simplify the page to f-¹(x) ... but in the intro I say "So the inverse of:   2x+3   is:   (y-3)/2" and that does not sit well with using f-¹(x)

Nor with the table of inverses as ganesh mentions.

I polished it specially for the occasion!

I will mention The law of reflection, thanks ganesh.

I might put the typical hearing sensitivity graph just below the sound generator so people don't freak out though!

I was thinking of a popup edit screen, one line per object, with mass, x and y position and velocity magnitude and direction (0-360 degrees). The animation would pause while editing. Can also delete a particle.

LOL bobby!

I do hope to add more pages ganesh.