Suggestion for first figure in 25.4

[Nikos Gianniotis]

It may be useful to show the points a,b and c in the first figure of 25.4 (even though the mean value theorem does not help us find c but only assures us of its existence).

[john verzani]

Thanks for the suggestion. This should appear in the next update.

[hex4lcodes]

Hi, the binder notebook returns an unknown image error. Could you please fix?

[john verzani]

Thanks, I added two new links and directions to use colab.

I modified this page: https://jverzani.github.io/CalculusWithJuliaNotes.jl/precalc/julia_overview.html

If you found the binder links elsewhere or have thoughts on where they should be, let me know.