Not only is the symbol daunting, but the words are too

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Homework Help Overview

The original poster is examining the properties of the field \(\mathbb{F}_2\), specifically questioning its classification as a field and the implications of its operations. The discussion revolves around the definitions and axioms that characterize fields, particularly focusing on the unique properties of the set \{0, 1\}.

Discussion Character

  • Conceptual clarification, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants explore the meaning of "curious field" and its implications for the properties of \(\mathbb{F}_2\). There are attempts to verify axioms related to addition and multiplication, with questions about the validity of operations like \(1 + 1\) and the existence of additive inverses.

Discussion Status

The discussion is ongoing, with participants providing insights into the definitions and properties of fields. Some guidance has been offered regarding the verification of axioms, but there is no explicit consensus on the interpretations or methods to apply.

Contextual Notes

Participants are navigating through potentially confusing definitions and properties, with some expressing uncertainty about the axioms and their application to the field \(\mathbb{F}_2\). There is a noted lack of clarity regarding the operations defined for this field and how they differ from standard arithmetic.

  • #31
flyingpig said:
2.46 and 2.47? I had my doubts...

What in Earth do you mean with 2.46 and 2.47?
 
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  • #32
micromass said:
What in Earth do you mean with 2.46 and 2.47?

[PLAIN]http://img707.imageshack.us/img707/652/unledfz.jpg

Sorry lol, I was reading in my mind.
 
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  • #33
And how would you evaluate

1 + (0 + 1)

using those rules?
 
  • #34
1 + (0 + 1) = 1 + 1 = 0
 
  • #35
And how would you evaluate (1+0)+1 ?? Is it also 1??
 
  • #36
micromass said:
And how would you evaluate (1+0)+1 ?? Is it also 1??

(1 + 0) = 1 from 2.46

so I get 1 + 1 = 0 still

Also RedBelly I was actualyl going to post my answers lol and then it said "Sorry! the thread is locked!"

Flyingpig to Redbelly (unrelated to this thread) said:
Never mind d) is 375. They all move up by 75...each. Stupid question.

This was solutiuon they gave me

[PLAIN]http://img849.imageshack.us/img849/4906/unledhsb.png

Which just means the answer is a multiple of 5, I thought they meant the contours are "5M units apart"
 
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  • #37
OK, so that is indeed correct. We indeed have that

1 + (0 + 1) = (1 + 0) + 1 = 0

But that is not were the error was. The error is in the following

1 + (1 + 0) = (1 + 1) + 0 = 1 + 0 = 1

So can you calculate

1+(1+0)=...
(1+1)+0=...

again and see where the error is?
 
  • #38
micromass said:
So can you calculate

1+(1+0)=...
(1+1)+0=...

again and see where the error is?

But they all arrive at the same answer

1 + (1 + 0) = 1 + 1 = 0

(1 + 1) + 0 = 0 + 0 = 0

But 1 + (1 + 0) from A2 says 1 + (1 + 0) = (1 + 1) + 0 = 0 + 0

I don't see the error
 
  • #39
flyingpig said:
But they all arrive at the same answer

1 + (1 + 0) = 1 + 1 = 0

(1 + 1) + 0 = 0 + 0 = 0

But 1 + (1 + 0) from A2 says 1 + (1 + 0) = (1 + 1) + 0 = 0 + 0

I don't see the error

Indeed, they are all 0. But before you said that it was equal to 1. So now you have the correct answer.
 
  • #40
Impossible I had 0! It was in post#29!

Oh well at least I got the other 7 right! ahahhaah

Wait, does that mean I will have 8 x 8 = 64 lines to write for all the other ones...?
 
  • #41
Correction * 64
 
  • #42
Yes, now try to do the other ones. This should be quite easy if you understood this one.
 
  • #43
oH MY GOD, Please stay with me in case I made a silly mistake. With 64, I will...
 
  • #44
A1 done, A2 speaks for itself.

A2 said:
x + y = y + x

Let x = 0, y = 0

0 + 0 = 0 + 0 = 0

Let x = 0, y = 1

0 + 1 = 1 + 0 = 1

Let x = 1, y = 0

1 + 0 = 0 + 1 = 1

Let x = 1, y = 1

1 + 1 = 1 + 1 = 0

OKay probably not 64 then

A3 said:
I sense danger from this one...

x + 0 = x

Let x = 0

0 + 0 = 0

Let x = 1[/tex]

1 + 0 = 1



A4 said:
x + (-x) = 0

Oh boy

Let x = 0

0 + (-0) = 0 + 0 = 0

Let x = 1

1 + (-1) =...

Stuck already...I am an idiot

DOing M1-M4 D in another post.
 
  • #45
OK, for A4, you need to use that -1=1 and -0=0. You define this to be so.
 
  • #46
M1 said:
Damn it, 8 cases again

(xy)z = x(yz)

Let x = 0, y = 0, z = 0

(0*0)0 = 0(0*0) = 0*0 = 0

Let x = 0, y = 0, z = 1

(0*0)1 = 0(0*1) = 0*0 = 1

Let x = 0, y = 1, z = 0

(0*1)0 = 0(1*0) = 0*0 = 0

Let x = 1, y = 0, z = 0

(1*0)*0 = 1(0*0) = 1*0 = 0

Let x = 1, y = 1, z = 0

(1*1)0 = 1(1*0) = 1*0 = 0

Let x = 1, y = 0, z = 1

(1*0)1 = 1(0*1) = 1*0 = 0

Let x = 0, y =1, z = 1

(0*1)1 = 0(1*1) = 0*1 = 0


Let x = 1, y = 1, z = 1

(1*1)1 = 1(1*1) = 1*1 = 1

M2 said:
xy = yx

Let x = 0, y = 0

0*0 = 0*0 = 0

Let x = 0, y = 1

0*1 = 1*0 = 0

Let x = 1, y = 0

1*0 = 0*1 = 0

Let x = 1, y = 1

1*1 = 1*1 = 1

M3 said:
Other than 0, there is a 1 such that x * 1 = x

Let x = 0

0 * 1 = 0

Let x = 1

1*1 = 1

M4 said:
Other than 0, we have an inverse for x

Oh wait...should I just do x = 1 case...?

D said:
NOOO ANOTHER 8 CASE. I'll be back on this one...

Need water...be back in 2 mins.
 
  • #47
The second of M1 is incorrect.
 
  • #48
Yes because 0*0 is not 1...!

D said:
Let x = 0, y = 0, z = 0

0(0 + 0) = 0*0 + 0*0 = 0 + 0 = 0

Let x = 0, y = 0, z = 1

0(0 + 1) = 0*0 + 0*1 = 0 + 0 = 0

Let x = 0, y =1, z = 0

0(1 + 0) = 0*1 + 0*0 = 0 + 0 = 0

Let x = 1, y = 0, z = 0

1(0 + 0) = 1*0 + 1*0 = 0 + 0 = 0

Let x = 1, y = 1, z = 0

1(1 + 0) 1*1 + 1*0 = 1 + 0 = 1

Let x = 1, y = 0, z = 1

1(0 + 1) = 1*0 + 1*1 = 0 + 1 = 1

Let x = 0, y = 1, z = 1

0(1 + 1) = 0*1 + 0*1 = 0 + 0 = 0

Let x = 1, y = 1, z = 1

1(1 + 1) = 1*1 + 1*1 = 1 + 1 = 0

I am pretty confident in this one
 
  • #49
Looks ok!
 
  • #50
Now just imagine I have to put all of this on paper.
 
  • #51
SammyS said:
For this field, -1 = 1 . This is because the thing you need to add to 1 to give you the identity element for addition is 1.

micromass said:
OK, for A4, you need to use that -1=1 and -0=0. You define this to be so.

I overlooked something. since WHEN DID I DEFINE -1 = 1?
 
  • #52
Well, you need to find for each x, an element y such that

x+y=0

By definition, this element is -x.

So, for x=0, you need an element such that 0+y=0. When you look at the axioms, you see that y=0 is the only possibility. So -0=0.

Now, what is -1?
 
  • #53
Oh is it from 1 + 1 = 0, that 1 = -1? oh okay
 
  • #54
flyingpig said:
Oh is it from 1 + 1 = 0, that 1 = -1? oh okay

Yes.
 
  • #55
I am still stuck on M4...
 
  • #56
Take x in your field. How would you define x^{-1}??
 
  • #57
xx^{-1} = 1

x^{-1} = 1/x

That doesn't change the original definition...

I still can't use 0.
 
  • #58
Oh wait, M4 actually states for all x in R, without 0, the axiom holds, I don't even need to test x = 0 right?

Ah shoot for M3, I put 0 * 1 = 0, that's wrong isn't it? Because it says x without 0
 
  • #59
Sigh...

For each x nonzero, you need to find a y such that xy=1.
If x=1. What can you take as y?
 
  • #60
flyingpig said:
Oh wait, M4 actually states for all x in R, without 0, the axiom holds, I don't even need to test x = 0 right?

Right.
 

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