# Thread: Hmmm....1=2. Any Explanation?? :D

1. ## Hmmm....1=2. Any Explanation?? :D

I came across this image which was someone's signature in some forum whose name i can't remember. Its a serious mind twister and surely makes you think.

Well, i've come to one conclusion and will disclose later. What do you guys have to say?

2. The mathematical procedure is flawed. This image is invalid.

Why? Because you can't divide by zero.

3. Originally Posted by Kovich
The mathematical procedure is flawed. This image is invalid.

Why? Because you can't divide by zero.
Ahh..nice. Good answer, wasn't expecting the first person to figure it out. Sad this couldn't turn into a discussion though.

4. Haha, sorry! Math is my strongest point next to various fields of Science. :P (I'm a Biochemistry major.)

We can still discuss it though... xD

5. Originally Posted by Kovich
The mathematical procedure is flawed. This image is invalid.

Why? Because you can't divide by zero.
Maths isn't my best thing on school, so here goes the first question Where in this image is something divided by zero?

6. Well, the first statement says that a=b. Therefore, b-a is zero.

The best way to figure something like this out is to substitute a number for the variable, and since A is equal to B we'll just assign 1.

1 = 1
1^2 = 1
1^2 + 1^2 = 1^2 + 1
2(1^2)-2(1) = 1^2 + 1 - 2(1)
2(1^2) - 2(1) = 1^2 - 1
2(1^2-1) = 1(1^2-1)

Simplified:
1 = 1
1 = 1
1 + 1 = 1 + 1
2 - 2 = 2 - 2
2 - 2 = 1 - 1
0 = 0

7. Net Builder
Join Date
Jan 2009
Posts
152
The problem is in the last step, where we have (a^2 - ab) on both sides and then cancel it out. Now, if a = b (as stated at the beginning), then (a^2 - ab) = 0 (which is just a rearrangement of the second equation). So, in the last step, we are dividing both sides by zero to cancel out the (a^2 - ab) part. The second-to-last equation is really 0 = 0.

Edit: ah, Kovich beat me to it.

8. Aha, I haven't thought like that about it Thanks for explaining!

9. It took me atleast 10 close reads to figure out the mistake when i had first found out this image. The way it has been made is really smart i must admit