Measure Theory Interblog

Found this on Reddit

I revamped my online tutoring website a few weeks ago. Among the changes I made was a form where people could send me a message directly from the site. I thought that since it saved people from copying my email address and logging into their email, I might get a few more emails. So far, I’ve received 12 messages in the past 24 days - which is about 11 more messages than I usually get in any 24 day period. But, even as the quantity of messages increases, the quality hasn’t. And I haven’t ended up with any more business than I would normally have had.

Here’s a recent exchange I had:

WILL U HELP ME WITH MY MATH PLEASE

—

Hi

I’d be happy to help you out. What sort of troubles are you having?

Jeff

—

ok

Now, I studied math and economics, not english. But, I’m reasonably certain that there’s no conceivable way that “What sort of troubles are you having?” could possibly be answered with “ok”.

(Shortly I’ll post some more of the crazier email exchanges I’ve had)

The 6, 7, 8 phenomenon. I thought I was the only one who experienced this!

(Not to be confused with the 7, 8, 9 phenomenon)

It’s more physics-related than math-related, but I found it funny

A different kind of captcha:

(from Reddit)

I do online tutoring. This was one of the questions that someone sent me:

1) Solve this equation:   -10x-6+4x=-4x+8

2) x + 7x = 8x

Number 1 seems ok. Number 2 perplexes me.

I just stumbled onto a math community on Live Journal. Considering the frequency that I Google “math AND sex”, it’s amazing that I didn’t turn this up before now.

Mathsex Community

(There appears not to be as much sex as there is math. Some kind of false advertising or something)

I just finished tutoring a student. We were finishing up differentiation and starting up antidifferentiation. I told her not to worry too much about what the “squiggle” and the dx meant and instead to think of them as enclosing the part that you’re meant to integrate. So far, so good. Until we got to a question that had dv instead of dx. The class is introductory and doesn’t have any double or triple integrals and it doesn’t have any kind of integration of multivariable functions. So, it wasn’t a big deal. But, she asked why it was dv now.

“Well, I lied…it sort of indicates what variable you’re supposed to integrate”

“…ok…”

“….so, if it said xv dx, then you’d know you were integrating over x and you’d pretend the v wasn’t changing”

“…”

“I probably made things a lot worse. Ignore what I just said”

“That’s ok. I wasn’t really listening”

Another thing. We covered a lot of material lately. Produce rule, quotient rule, chain rule, optimization, higher derivative, etc. And then we’ll come to a question where the function (or one of it’s derivatives) is constant. We’ll have f(t) = 12t and f’(t) = 12 and the question will ask what the speed is after 4 seconds. And we’ll have done the exact question 3 minutes before with a much harder function. And she’ll have no idea. Constant functions bother her.

Me: So, it’s just 12 right?

Her: Right……….wait why?

Me: Well, the derivative is just 12. So, it’s 12 everywhere.

Her: …

Me: So…when t = 4, f’(t) is going to be 12 right?

Her: Riiiiight….wait. What?

Me: Well, how would you get f’(4)?

Her: Replace all the t’s with 4’s. But there are no t’s!!!

She can do exponential functions, logarithmic, polynomials and plenty of difficult combinations of these. But when she gets to a constant function, it just doesn’t happen.

It’s always strange how some people understand difficult concepts more easily than typically harder ones (she got the chain rule in about 10 seconds - something that I’ve had people struggling for weeks with).