If you already know a thing or two about web design, you can skip around a bit. Otherwise I hope my phrasing is easy to understand.
This graphing calculator started as a way to display different functions from the Interpolation experiment. I thought it was pretty cool so I made it more modular and put it into its own experiment, making it editable with a somewhat intutive user interface. I mostly made it just for fun, but it was also to prove to myself that even someone less than a year out of high school could program a competent graphing calculator.
It took a lot more math to display even a basic graph than I previously expected. I can't just map X and Y pixel values to whatever function is used since not only is (0,0) at the very top left of the rendered graph, but also the direction of positive Y is down, which isn't too helpful for a graph. Also, pixels are really small, so it would be hard to see small graphs. Long story short, I did some math to convert pixels to units using any given window and X/Y resolution.
This one is a parabola!
Separate different lines with a semicolon
Is this even useful?
Smooth sin() interpolation