Captchas gone bezerk!

[giza]

From http://random.irb.hr/signup.php:



Um, yeah... I sure wish I paid attention in Calc I back in high school!

Comments

[simbab.livejournal.com]

Holy shit. I was in a calc class not but a few months ago and I don't think I could answer that...thank goodness I have a TI-89 calculator for that!

[silverscalenaga.livejournal.com]

ti-89 will not do partial differation.

[snowhusky01.livejournal.com]

I think my eyes just crossed, we never had to do anything like that in calc

[balinares.livejournal.com]

This is awesome. Not only does this filter spambots, but it also filters goons. We should do more of that. :D

[unciaa.livejournal.com]

I also love how all the questions are actually trivial questions. I made myself an account just to see if I was right. *g*

[unciaa.livejournal.com]

Trivial -trick- questions. Overediting go.

[balinares.livejournal.com]

Not all of them are trick questions, seems like; trick questions are possibly just special cases of their random question generator from what I can tell, for instance asking for the differentiation in x of a function that doesn't have an x variable. Still, this is brilliant. :D

[unciaa.livejournal.com]

Well, I count "this collection of information just happens to be trivially solvable" as a trick question. Like asking for the least real zero of a polynomial, where ALL the non-zero ones are the same. Or, sin/cos function with variations of Pi/2 inside that always result in 1/-1/0.

IE, with -any- other combination of variables it'd be tricky. With the one given? There's at least a 50% possiblity you can guess the result without even having to read up on those sections again.

[felix-carni.livejournal.com]

"Just to prove you are human"..
The way to prove you're human is to write anything BUT the correct mathematical solution :P

[sagejackal.livejournal.com]

Touché!

[sagejackal.livejournal.com]

Sorry, I don't live in an ivory tower. ;p

[sidepocket-pro.livejournal.com]

Like another person said...

This should be not a test to see if you are a human.

This should be a test to prove you are Asian. XD

[kuddlepup.livejournal.com]

Pi r round...not pi r squared

[jessypie.livejournal.com]

I know I didn't feel like I learned anything in calc class while I was IN it, let alone remembering it twelve years later...and I'm guessing we had the same teacher.

[This is kind of a trick question, though - it's asking you to solve where x=pi, which means you're doing the cosine of 1.5pi and since cos is a function of pi to begin with, everything cancels out and you end up with d/dx[0]. I don't know if that means the answer is 0 or if d/dx[0] means something else, though. That's the only actual calculus bit in the problem and that's the part I don't remember.]

This is kind of hysterical and only MARGINALLY more difficult than reading some of the garbled text some websites like to use to make you prove you are a human. I hate those things.

...

HA! I went to the website you linked to and got a problem similar to the one you posted above (different numbers, but still with the cosine/pi combo) and followed the instructions to reload the page for a different equation, and the second time around it gave me:

Q: -2 + (-2) + 2 * (-3) * 1 = ?

And then I reloaded it again and it was an algebra problem.

[ex-purpleca.livejournal.com]

The question requires that you differentiate first and then plug pi in to find the answer, not the other way around. That route wouldn't give any meaningful results - the object of differentiation is to find the slope of the graph of a function (or rise/fall rate), optionally at a given point (pi, in this case). So they'd need to differentiate first and end up with:

-8sin(2x-(pi)/x)

Then solve for x=pi

-8sin(2(pi)-(pi)/x) = -8sin(3pi/2) = -8 * -1 = 8.

It's not a trick question, but they're nice enough to provide an x value that's easy to solve and represent. It'd be hard to enter something like '2.958389294922blahblahblah' in the webform... ;)

[ex-purpleca.livejournal.com]

Whoops - typo. I meant

-8 * sin(2x-(pi)/x), not -8sin(2(pi)-(pi)/x).

[jessypie.livejournal.com]

OH, that makes sense! I couldn't remember what to do with the d/dx bit, so I just tried to solve the half I understood. :) I've always meant to try to revisit calculus and see if it made more sense to me outside of my high school classroom. I scored well enough on the calc AP test to test out of calculus in college, and I just never looked back after that...

I'm amazed!

[mbala.livejournal.com]

You can simply see the answer with no real diferentiation. It is slope of cos at 3PI/2 which is 1, times 4 (it is four times taller), times 2 (it is 2 times denser for the 2x).. voila 8. You don't even have to know that cos' = -sin

[girtygrin.livejournal.com]

It gave me P(x)= (x+2)(x+4)(x-5)

But then it asked to find the least real zero. I didnt read that bit untill I finished reducing it to p = x^2+x+-22+(-40/x)

Then I realized I did something wrong, balled it up and put it in the trash.

[two-pi-r.livejournal.com]

The least real zero of that is rather obviously -4. :P

[fc-greyfox.livejournal.com]

*boggles* Uhm... Yeah. That's the sort of thing computers were designed to calculate. Anyway, even if I -had- payed attention in Calc class, the teacher herself was clueless and blithering on! It would have been a miracle if anyone picked up anything in that class at all. Anyone have a spare calculus text lying around that actually makes sense?

[two-pi-r.livejournal.com]

twopir@speare5-1-13:~ $ maple
    |\^/|     Maple 10 (IBM INTEL LINUX)
._|\|   |/|_. Copyright (c) Maplesoft, a division of Waterloo Maple Inc. 2005
 \  MAPLE  /  All rights reserved. Maple is a trademark of
   Waterloo Maple Inc.
      |       Type ? for help.
> diff(4*cos((2*x)-(Pi/2)),x);
                                                            8 cos(2 x)

[two-pi-r.livejournal.com]

Oh. Shit. I didn't see it wanting the differential at x=Pi. And I don't know how to do that in Maple. Fuck. D:

I'm amazed!

[mbala.livejournal.com]

You set x=PI and correctly obtain 8 cos(2PI) = 8. You don't actually need Maple for that.

Re: I'm amazed!

[two-pi-r.livejournal.com]

I'm _very_ rusty on my calc.

[coyoteden.livejournal.com]

I love it. A CAPTCHA that not only defeats spambots, it makes users run away screaming!

Here's one I thought of: You have to click on the "bullseye" in the image. The "bullseye", of course, moves around...

...the image is goatse.

[rexxwolfe.livejournal.com]

I cant do basic math well let alone that.

[nrr.livejournal.com]

Chances are most likely that you wouldn't've learned this in high school. ;)

For what it's worth, this is multivariate calc, and that's usually third-semester coursework in the university way of doing things.