some funny stuff i found on facebook

[mahlertitan]

math related jokes

[Mozart]

The 4th one is great! The 3rd one is pretty funny too.

[Mahler Symphony]

I love these! The third and the fourth are the best.

[XB-70 Valkyrie]

Is this your homework, Larry?

[George]

Is this your homework, Larry?

[маразм1]

Lol!!  erf??



taken from http://www.haha.nu/funny/funny-math

[George]

Lol!!  erf??



taken from http://www.haha.nu/funny/funny-math

I can't figure that one out. 

[DavidW]

I can't figure that one out. 

It's an optical illusion.  Look at one triangle, count the number of number of cells on either leg, the ratio is the slope of the hypotenuse.  The slope of either should be equal if it is a triangle.  But what do you find?  8:3 vs 5:2, they actually have different slopes!  The make them look the same by (a) having slopes that are close to each other, but still not equal and (b) curving the hypotenuse of either one just a little bit so that they'll still match.

If the slopes were equal, you would really have a triangle, and thus expect that the areas should be the same in both cases.  But because of that little bit of curving to make the unequal sloping hypotenuses match you actually end up with an area discrepancy so that if you did the same trick with the triangles in different places you end up with more area.

[mahlertitan]

It's an optical illusion.  Look at one triangle, count the number of number of cells on either leg, the ratio is the slope of the hypotenuse.  The slope of either should be equal if it is a triangle.  But what do you find?  8:3 vs 5:2, they actually have different slopes!  The make them look the same by (a) having slopes that are close to each other, but still not equal and (b) curving the hypotenuse of either one just a little bit so that they'll still match.

If the slopes were equal, you would really have a triangle, and thus expect that the areas should be the same in both cases.  But because of that little bit of curving to make the unequal sloping hypotenuses match you actually end up with an area discrepancy so that if you did the same trick with the triangles in different places you end up with more area.

what? i thought the slopes are the same, rise/run, so isn't it 5/13 for both cases?

[DavidW]

what? i thought the slopes are the same, rise/run, so isn't it 5/13 for both cases?

You implicitly assumed that the slopes were the same to arrive at 5/13.  Do them individually, you're actually looking at a quadrilateral that is very close to being a triangle.

[George]

It's an optical illusion.  Look at one triangle, count the number of number of cells on either leg, the ratio is the slope of the hypotenuse.  The slope of either should be equal if it is a triangle.  But what do you find?  8:3 vs 5:2, they actually have different slopes!  The make them look the same by (a) having slopes that are close to each other, but still not equal and (b) curving the hypotenuse of either one just a little bit so that they'll still match.

If the slopes were equal, you would really have a triangle, and thus expect that the areas should be the same in both cases.  But because of that little bit of curving to make the unequal sloping hypotenuses match you actually end up with an area discrepancy so that if you did the same trick with the triangles in different places you end up with more area.

Surely I knew it would be you that would get this one, David! 

Yes, by looking at the hypotenuse of each of the two large triangles, it is clear that that is not a straight line, but rather a curved one on the second one. Good work! 

[mahlertitan]

okay i see it now, it's obvious that the slopes aren't the same, if you calculate from left to right, when X=5-6, the Ys are different.