# Thread: What is this method named?

1. ## What is this method named?

Let say I have to prove A = B. I assume that A is not equal to B and I derive that this assumption violates a well-known statement, meaning that this assumption is not true. Therefore A must equal B ( It is proven).

My question: What is this method named?

2. ## Re: What is this method named?

Algebara or geometry depending on the problem?????

3. ## Re: What is this method named?

Originally Posted by Searching for language
Algebara or geometry depending on the problem?????
The name of this method does not depend on a specific problem.
Let's say you have to prove that something is true, you assume that it is not true, you do things, and you end up with a conclusion that this assumption is wrong, then you get the proof.

4. ## Re: What is this method named?

My 10th grade math teacher would know this. I remember using this method to prove that the square root of 2 is irrational, by starting by assuming it was rational.

We need a math teacher to stop by.

5. ## Re: What is this method named?

Originally Posted by Barb_D
My 10th grade math teacher would know this. I remember using this method to prove that the square root of 2 is irrational, by starting by assuming it was rational.

We need a math teacher to stop by.
Yes, I still remember this problem that you mentioned. But I could not recall the name of this method

Does anyone else have the answer?

6. ## Re: What is this method named?

I'd call it Logic or Logicism.

7. ## Re: What is this method named?

Originally Posted by marciobarbalho
I'd call it Logic or Logicism.
Thanks, but this method is less general than what you suggested.