Matt Enlow

In front of you are three coins, identical in appearance. However, while two of them are fair coins, the third comes up Heads 75% of the time. Your task is to identify which coin is the unfair one, but you may only perform a total of three coin flips! (For each flip, you can flip any coin you want, taking any past flip results into account.) After those three flips, you must declare which coin you believe to be the unfair one. Assuming you "play optimally," what is the likelihood that you will correctly identify the unfair coin after your three flips?

Okay this one is a beast

#math #mathchat #maths #mathschat #probability #iTeachMath #MathSky

Here's a fun Geometry quickie:

A particular polygon has only two distinct interior angle measures: 165° and 166°. How many sides does it have?

#iTeachMath

Me figuring out how to make Canvas API calls from Google Sheets

I do love questions like these, but I’m always conflicted about giving them on any kind of _timed_ assessment.

I vibe-coded a web app that allows you to walk around on the surface of a gyroid.

It's just as disorienting as you'd expect.

velvety-arithmetic-0a8353.netlify.app

It's kind of a running gag in our house about how boring my Facebook posts were before we had kids, but this one kind of takes the cake

MAA MathFest is in Boston this year! I've never been, and always wanted to.

A significantly reduced registration rate for K-12 teachers? And I might be able to bring one of my kids as a "guest"? This may be my opportunity!

Anyone else I know planning on attending?

maa.org/event/mathfe...

Three words/phrases you never want to hear from your plumber when you're describing your problem over the phone: "absolute nightmare," "worst-case scenario," and "jackhammer"

Oh yeah! A fave 😁

Nice. I thought of it initially as the path a circle sweeps out as it both increases in radius and rotates about the x-axis, which gave me a double snail-shell kind of thing, but I wanted to see the spiral-y insides, so I cut it in half (thus t varying from -pi/2 to pi/2 instead of -pi to pi)!

I'm not sure you can see the ALT text in a GIF, so:

With[{k = \[Pi]/6}, ParametricPlot3D[{r Cos[t], r Sin[t] Cos[k r], r Sin[t] Sin[k r]}, {t, -\[Pi]/2, \[Pi]/2}, {r, 0, 18}, PlotRange -> All, PlotPoints -> 120, Axes -> False, Boxed -> False, SphericalRegion -> True]]

One superpower #math gives me is the ability to picture an interesting object in my head, spark up #Mathematica, and within a few minutes figure out how to make it "real." It's intoxicating!

(code in ALT)

Heh, I just happened to capture the section at which my reading rate screeched to a crawl. (My first encounter with a Hermite polynomial basis 🙃)

Reading by the light of heavy snowfall out the window behind me ❄️😊❄️

Just arrived 😍😍😍

Yeah we're not done yet 😁

After a few weeks of repeated discussion and revision, here is where the Axiom (& Theorem) List for ℤ that my Advanced Topics class has been generating from scratch—with some prodding and guardrails provided by me—currently stands. (Proofs of the Theorems are located elsewhere.)
#MathSky #iTeachMath

It's not like I struggle with wording them just so, though. I know what I want to say. I just can't muster the effort of clicking and typing and clicking and typing and... 🤷‍♂️

Why are the emails that require the meagerest of replies—"All set!" "Thank you!" "Great! See you then!"—sometimes the hardest to get myself to write?!? Makes no sense. Stupid #ADHD brain...

Student 1: I don’t get this.
Student 2: Oh! Let me show you a trick my tutor showed me.
Me: 😑🤐
S1: *shows S2*
S2: OMG, that is so EASY! Mr. Enlow, why didn’t you teach us this?!?
Me: 😑😑😑😑😑

Not great! 😬 I think I added too many supports, and they're super tough to remove (even though I printed it much larger than ring-size: ~4 inches in diameter?).

I always intended for it to be printed by Shapeways in metal, anyways...

This does feel like the unstoppable force/immovable object of a lot of math ed...

YouTube video by MooMooMath and Science Factoring Trinomials ( Easy X Method )

There is 😁

youtu.be/CH4jYzajkp0?...

😍😍😍

YouTube video by MooMooMath and Science Factoring Trinomials ( Easy X Method )

youtu.be/CH4jYzajkp0?...

Full disclosure: I do actually teach a version of this without the X, so I’m not opposed to this shortcut altogether. I just see a lot students using it (or TRYING to use it) in ways that show a significant lack of understanding.

Please stop teaching the "X method" for factoring.

And please de-stigmatize "guess-check-revise."

Yes, it's slower. But it yields SO much more actual learning and understanding than blindly following an algorithm does.
#iTeachMath #MathSky

I notice that there is more subdivision going on than was present in the Mathematica mesh. So something's doing more work somewhere!

Huh. Either Mathematica's Export process or MeshLab's Import process seems to have just... figured it out

I think there might be a simple way to accomplish this (properly orient faces) in MeshLab.

According to RepairMesh (and FindMeshDefects), there’s nothing to repair! 🤷🏼‍♂️