Gabe Kramer

Math Help: If I have a nonlinear transformation T: R^m -> R^n, what do I call the set of solutions to T(x)=0? Is it just roots or zeros? Or is there a fancier name for it?

Hear me out: Instead of multiple classes meeting 3-4X a week for 15 weeks. One class meets 3-4 hours per day (2 hour morning session + 2 hour afternoon session) for 15 days.

@CmonMattTHINK Here's another good one.

Produce these two disks with a single inequality.

@minkbazink Poser?

@CmonMattTHINK If you take the set of irrationals and add the same irrational to each element, the new set contains every rational number.

Wait, why is this blowing my mind. If you take the set ℚ of rationals, and multiply every element by some fixed non-zero rational number (like, say, 355/113), ... do you just get... ℚ again? I mean, really. Somehow that is both totally obvious and totally mind-blowing.

@mrdardy I’ll see you there! I’m doing calculus.

Super excited to be on my way to my first AP grading. Heading to Kansas City to grade AP Precalculus this year. Just settled in at my first of three airports today

@CmonMattTHINK f(x) = 0, x<=0 = x^2, x>0 g(x) = sin(x) - 3

@CmonMattTHINK Can you do it with two differentiable functions?

Me, to me: Do there exist functions f & g such that neither one is constant, but f(g(x)) is constant? Me (after a few minutes): Yes. Me: Okay, so... What if f & g have to be continuous? Me:

Some geometry of the dot product: desmos.com/3d/5oazs3wlcn.

@Desmos I had a little bit of fun with it. desmos.com/calculator/eqn…

I believe the technical term is "blobby object." → Explore the graph: desmos.com/calculator/92d…

@Canvas_by_Inst there has to be a better way to do this.

Is anyone else having the issue in Chrome where @Canvas_by_Inst isn’t giving the option to delete objectives?

@mrdardy This throws me off every time I teach polar functions. Because I usually think of ordered pairs as (independent, dependent), but with polar it’s flipped.

Can someone fill me in on a math history/notation question? We are discussing Polars in AP PC and it has always struck me that the (r, theta) coordinate is backwards. Feels much more useful to know direction first , then think about directed distance. Why is it in this order?

Formula sheets on exams.

@MrCorleyMath @Trianglemancsd @MathHappensOrg @Desmos That sounds like a challenge Mr. Corley.

@Trianglemancsd @MathHappensOrg Now, make it in @desmos. Who can use the LEAST # of expressions to do it?

@Mr_DSchulte @desmosclassroom I use it daily, and most of my department uses it quite often. Younger faculty are quicker to adopt it, but once most folks realize you don’t need a degree in computer science to display graphs they are apt to jump in and use it. As far as activity builder goes..different story

I’m curious about any insight from the math community…are colleges/universities using Desmos in their courses? I know Desmos is embedded in the PSAT and on track to be on the digital SAT…if it’s not already embedded. #mtbos #mathed #iteachmath @desmosclassroom

Behrend is hiring! TT Position in MathEd psu.wd1.myworkdayjobs.com/en-US/PSU_Acad… NTL Position in Math psu.wd1.myworkdayjobs.com/en-US/PSU_Acad…

Been seeing lots of @Desmos 3D discussion around surfaces of revolution for Calculus. While parametrics are great for showing the act of rotation (see: desmos.com/3d/1a7f86ac77), I'm also loving this strategy, accessible to students who have seen equations of circles before: