So... Who likes math?

[OneJoeZee]

I have a harder one if you guys would like to try.

 

[annoyingrob]

I have a harder one if you guys would like to try.

do it.

 

[SupraDerk]

You have to look at the proof in relation to the steps. Telling me that the expanded equation is equal to zero, which is ok, doesn't explain why step 4(in particular) and the following steps that result in 2 = 1 are false.

Ok here is the explanation of my explanation.

(a+b)(a-b) = b(a-b) ... just looking at that (a-b) equals zero. You have it on both sides... so whatever you do both sides will equal zero. You will have NOTHING to divide over to the other side, nothing to give you an invalid solution because (a-b) is zero!!

(a+b)(0) = 0
b(0) = 0

0=0... what are you dividing over?? Absolutely nothing and even if you try... 0/0 = 0... nothing divided by nothing is NOTHING... so that is why ever step beyond it is wrong

 

[OneJoeZee]

You have to remember we're talking about a proof that isn't even a true proof. It's fabricated to show the error in dividing by zero and what can go wrong. Why is the proof 2=1 wrong, not why is step 3 wrong.

Step 4 isn't 0=0. Step 4 is (a+b)=b. So your answer has to reflect why Step 4[ (a+b)=b ] and it's result 2=1 is incorrect. This is why Rob's anwer is correct for this 'proof' that 2=1 by showing the error of division by zero... even though both of your answers are mathematically sound.

 

[Sawbladz]

(a+b)(a-b) = b(a-b) does not mean (a+b) = b. What you are doing is dividing the first equation by zero (a-b) to give yourself the second equation, which is mathematically incorrect.

And THAT's why this proof is false.


It didn't take abstract algebra in university for nothing

I'm pissed I didn't see this earlier cause I got that answer...then realized there were 3 pages of replies. Good work.

 

[SupraDerk]

You have to remember we're talking about a proof that isn't even a true proof. It's fabricated to show the error in dividing by zero and what can go wrong. Why is the proof 2=1 wrong, not why is step 3 wrong.

Step 4 isn't 0=0. Step 4 is (a+b)=b. So your answer has to reflect why Step 4[ (a+b)=b ] and it's result 2=1 is incorrect. This is why Rob's anwer is correct for this 'proof' that 2=1 by showing the error of division by zero... even though both of your answers are mathematically sound.

If step 3 is wrong, then that would be evidence enough to show that the proof of 2=1 is wrong.

Proof by contradiction... show one case where the "proof" that you're trying to prove fails

 

[themadhatter]

(a+b)(a-b) = b(a-b) is wrong the correct answer is (a+b)(a-b)=a^2-b^2

^= to the power

 

[aaronmancilla]

whats the question?

 

[aaronmancilla]

you can approach it as a direct proof or as a negation proof...
aaron

 

[aaronmancilla]

the proof is actually
If a=b and a,b>0, then 1=2, the
proof has a prblem when you said (a+b) = b , why for the fact that a=b-b=> a=0, and the condition states that a,b> 0, therefore it is wrong, keep in mind that a,b belong to the natural numbers...QED

 

[aaronmancilla]

i know because i am a math major

 

[CFSapper]

I sorta understood that.:icon_conf

 

[ValgeKotkas]

Absolutely nothing and even if you try... 0/0 = 0... nothing divided by nothing is NOTHING... so that is why ever step beyond it is wrong

Nothing divided by nothing is actually Error:icon_bigg

 

[OneJoeZee]

yep

 

[slidebabyslide]

man, i need to learn math.....lol. I was never good at it, even in college i just look at the numbers and i can't figure it out.

 

[bigaaron]

This kid LOVES this thread!

 

[SupraDerk]

Nothing divided by nothing is actually Error:icon_bigg

Use your your brain and not a calculator or computer...

If I start out with nothing... and I try to add nothing to it, divide it by nothing, multiply it with nothing or subtract nothing from it... what is my end result?

Oh damn... nothing.


-----------------
You get errors and what not in simulations and computations by dividing by zero, because that'll result in a "not a number" (it'll be a flag that something went wrong) so that a computer can finish running a computation and be able to output an error

 

[OneJoeZee]

Dude.... zero divided by zero is not zero. ANYTHING divided by zero is undefined or indeterminate, even if you're dividing by zero.

I don't know how many times it has to be said. This is a theoretical concept just like many other things in math. The concept that anything devided by zero is undefined does not allow for 0/0 to be an exception.

http://mathforum.org/library/drmath/view/55675.html

http://mathforum.org/library/drmath/view/55971.html

http://www.math.utah.edu/~pa/math/0by0.html

http://www.insolitology.com/other/division.htm

How many sources should I cite? Dividing zero by zero does not result in zero.

Your answer to the proof problem was wrong and your theory about 0/0=0 is also wrong. Sorry.

 

[ret]

Use your your brain and not a calculator or computer...

If I start out with nothing... and I try to add nothing to it, divide it by nothing, multiply it with nothing or subtract nothing from it... what is my end result?

Oh damn... nothing.


-----------------
You get errors and what not in simulations and computations by dividing by zero, because that'll result in a "not a number" (it'll be a flag that something went wrong) so that a computer can finish running a computation and be able to output an error

You can't divide by zero, period. Why? Because nothing CAN'T go into something. How many times does 0 go into 50? How 'bout 100? Infinite? Same answer, it can't.

Oh, and according to your logic, 0/0 should equal 1, but it still doesn't.

 

[SupraDerk]

Did I say 0/0 in my last post?? No I said "nothing"! If I have nothing how can I do anything with it? There IS a difference in the wording so DO NOT put words into my mouth and take the time to READ and COMPREHEND what I type.

Anyways I'm done with this thread.