Edit: Melis have removed this joke from MIT admission blog after my comment on the 10 things I love about MIT
OK, Mgccl, I have removed the joke from the math entry. I had received your previous email and didn't remove the joke at the time because I thought that it was clear that these were jokes and therefore not factually accurate (I hope you don't take everything in xkcd as true. Helicopters don't get cancer.) While it is admirable that you took the time to correct the joke, for everyone's future reference, it's advisable NOT to use jokes as your source of knowledge on tests...textbooks are more reliable.
Some time ago, I had pointed out a mathematical flaw in the famous study = fail joke.
Now, I saw another unforgivable math joke that's completely wrong.

It's featured on MIT Admissions blog. No one commenter spotted it? Come on MIT, you could do better.
Someone is WRONG on the internet. and I have to fix it. I love how xkcd comic knows exactly what I'm thinking about.

Let's not talk about the implied stereotype of women in mathematics that tries to make this joke funnier, because that's nothing compare to getting the basic understanding of limit wrong.
Definition of limit according to wikipedia:
Let f be a function defined on an open interval containing c (except possibly at c) and let L be a real number.

means that
for each real ε > 0 there exists a real δ > 0 such that for all x with 0 < |x − c| < δ, we have |f(x) − L| < ε.
A very convinient graph of the function 1/(x-8)
What did you know? according to the graph, there is no limit.
There are, of course, left-hand and right-hand limits. So the real joke should be something like this.


Really, letting math jokes like this going around can hurt people on their tests, I learned it the hard way.
There is a interesting point I can make to make this math joke correct.
If we don't consider this problem in the usual first year college calculus's extended real number line, where there are 2 different kind of infinity.
and
, but to consider it in real projective line, then that is correct.
But really. How can a student can't understand the material of 1st year college calculus and working on calculus on real projective line?
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You know that part about the
You know that part about the joke, you know the thing that makes it funny? it's kind of the fundamental part of a joke. Jokes are rarely politically/mathematically/phyically/whatever-ly correct. The point is that it makes you laugh, in this case the fact that ONE LIMIT approaches infinity and makes the problem look like a sideways eight is good enough to excuse it's mathematical transgression. For God's sake it's just funny, laugh.
Adding a sign to 8 won't
Adding a sign to 8 won't kill the joke right? why not make it more mathematically correct?
True.....
Well..... lets call it a WTF on MIT's part. Every self respecting mathematician knows about Right Hand and Left Hand limits and err... I am sure everyone got the hang of it, the graph might be like rubbing salt over the wounds :)
It's just a joke. I've
It's just a joke. I've explained it to non-calc people and they thought it was funny, they wouldn't have understood if you went into detail about how it's left sided and right.. I mean people know that anyway, the point that the person saw infinity as a sideways 8 is the funny part. Just laugh instead of analyzing it. Who uses math jokes on the internet to study for tests, anyway?
That would be me :(
That would be me :(
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