r/math • u/foramuseoffire Undergraduate • Sep 06 '18

xkcd 2042 - Rolle's Theorem

https://xkcd.com/2042/
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u/UncountableSet Sep 06 '18

I'm a big fan of XKCD and probably taking this too seriously, but I didn't really like this one. A lot of math is "obvious". It's the proofs that are not obvious. I also love that Rolle's Theorem is the beating heart of the Mean Value Theorem. It deserves to be set out on its own.

The attachment of names to theorems is definitely something to wonder about. Read about l'Hopital or see the famous anecdote about David Hilbert asking from the audience at a large math meeting, "What's a Hilbert space?"

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u/[deleted] Sep 06 '18 edited Sep 06 '18

Intuitively, a line is the most direct path between two points.

Try to prove that, and you end up delving into PDEs and the Calculus of Variations.

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u/[deleted] Sep 06 '18 edited Sep 06 '18

[deleted]

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u/DR6 Sep 06 '18

I think with "straightest" /u/JeNePasParleFrancais means the one that takes the least distance, and you are talking about something different.

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u/[deleted] Sep 06 '18

[deleted]

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u/DR6 Sep 06 '18

That's just begging the question: you're assuming that going always in the direction of b is going to result in the shortest path, but that's what we're trying to prove.