1 | initial version |
That is quite impressive for half a Sunday! I'd suggest to forget about the legend command and use text. Add the two lines
right after the plot of the cubic, ie as separate Graphics objects. I've tried this, the coordinates (3,-18) and (-3,18) put it in a nice spot within your animation. And with the text color, you don't need a little colored line telling the viewer what the label refers to. BUT did you notice the 0:+ instead of your curly braces formatting { } ?? The 0:+ needs curly braces around it as well, I swear I typed them, can even see them in Preview, but they get eaten when it's displayed. Likewise, instead of bullet points, you want plus signs to add the text elements.
Inserting 0:+ displays k with a + if positive, - if negative (in your version, you get a plus AND a minus sign if k<0). For more details than you ever want to know, see help('FORMATTING') There is still a weird instability for k=0, I wonder if that's coming from the math - maybe choose a range for k which does not hit zero exactly?