November 18th, 2008
by Valentin in Math fun
Did You Know That… 2=1?
No, this is not a commercial of any kind (trying to convince you that if you buy 1 you will get 2)! This is just a mathematical proof that 2=1. I remember that my math teacher in high school first showed me this. I was quite impressed! A few days ago I randomly encountered the proof and recalled it. Here it is:
X = Y X*X = Y*X ; Multiply by X X*X-Y*Y = Y*X-Y*Y ; Subtract Y*Y from both sides (X-Y)*(X+Y) = Y*(X-Y) ; Some standard conversions X+Y = Y ; Cancel out (X-Y) 2*X = X ; Use that X = Y 2 = 1 ; Divide both sides by X
Are you convinced now? 
Tags: Mathematical proof
December 2nd, 2008 at 3:57 pm
You just showed the stupid things that can happen when you divide by zero…
December 3rd, 2008 at 1:26 am
You are completely right. On the other hand I remember the first time I saw that as a child. I was quite impressed, because I was not able to figure it out!
I think this is a good way to increase the interest of the children in math. To show them, that if they don’t understand math, they could be easily tricked
December 3rd, 2008 at 8:15 pm
I guess that is true