Can anyone spot the error in this fallacy

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The discussion revolves around the mathematical proof that suggests if a + b = t, then a must equal b, which is proven erroneous. The key error arises when taking the square root of both sides of an equation without considering the plus/minus aspect, leading to incorrect conclusions about the equality of a and b. Participants highlight that the proof fails because it does not account for the possibility of different values for a and b while still satisfying the equation. The conversation emphasizes the importance of correctly applying mathematical principles, such as the square root and the implications of absolute values. Ultimately, the claim that all numbers are the same is dismissed as flawed reasoning.
  • #31
Sorry! said:
I think what you mean to say is all numbers within the sets are the same. Not all numbers are the same.
The set of numbers is a set.
 
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  • #32
jimmysnyder said:
The set of numbers is a set.

Yes but saying that set A has the same numbers as set B is far different from saying the numbers contained within the sets are the same. 1 is not the same as 2, however the set A {1,2} is the numbers as set B {2,1}
 
  • #33
Sorry! said:
Yes but saying that set A has the same numbers as set B is far different from saying the numbers contained within the sets are the same. 1 is not the same as 2, however the set A {1,2} is the numbers as set B {2,1}
I did not say that A has the same numbers as B. For instance, in the example I gave, A had 4 elements and B had 3. What I did say is that if you assume ... Hey wait a minute. You do know what mathematical induction is right? I am doing induction on the number of elements in the set. Do you understand what that means? Can you do an inductive proof that the sum of the first n positive integers is equal to n(n + 1) /2?
 
  • #34
Sorry! said:
We are not taking the square root of any negative numbers here.

In order to go from:

(a - t/2)^2 = (b - t/2)^2

To:

a - t/2 = b - t/2

Where a, b, and t are variables for all real numbers, then yes, you are...

Well, you're excluding have the input set, the half where either a-t/2 is negative, or b-t/2 is negative.
 
  • #35
jimmysnyder said:
I did not say that A has the same numbers as B. For instance, in the example I gave, A had 4 elements and B had 3. What I did say is that if you assume ... Hey wait a minute. You do know what mathematical induction is right? I am doing induction on the number of elements in the set. Do you understand what that means? Can you do an inductive proof that the sum of the first n positive integers is equal to n(n + 1) /2?

I thought what you were doing was using a,b,c,d to represent specific numbers. and in each set they would represent the same numbers. I do know what mathematical induction is though.
 
  • #36
mugaliens said:
In order to go from:

(a - t/2)^2 = (b - t/2)^2

To:

a - t/2 = b - t/2

Where a, b, and t are variables for all real numbers, then yes, you are...

Well, you're excluding have the input set, the half where either a-t/2 is negative, or b-t/2 is negative.

So I guess when I take I take:
\sqrt(1-2)^2 or
\sqrt(-3)^2
(the line should be over everything but I'm not great with latex.
I'm taking the square root of a negative number... interesting; never learned that in math.

Let's see what happens when we follow order of operations:
\sqrt(-3)^2=<br /> \sqrt(9)=+/-3

Where do we take the square root of any negative number?
 
  • #37
Where in the OP did it say real number? If a is i (imaginary) and t is 0, then a - t/2 is i and its square is -1. When you take the square root you will be taking the square root of a negative number. But that is not the flaw in the proof.
 
  • #38
jimmysnyder said:
Where in the OP did it say real number? If a is i (imaginary) and t is 0, then a - t/2 is i and its square is -1. When you take the square root you will be taking the square root of a negative number. But that is not the flaw in the proof.

lol, i think i hate you.

:-p

jkz :)
 
  • #39
Sorry! said:
jkz
ndrstd
 
  • #40
By the way, if you quote this post, it will show you how to extend the line of the square root symbol

\sqrt{(-3)^2}=<br /> \sqrt{(9)}=\pm3
 
  • #41
jimmysnyder said:
By the way, if you quote this post, it will show you how to extend the line of the square root symbol

\sqrt{(-3)^2}=<br /> \sqrt{(9)}=\pm3

OHHHH ok thanks. I tried using those [] brackets but it was just leaving a huge space. Thanks jimmy :smile:
 
  • #42
I am locking this thread. The OP has not been back since his initial post.
 

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