Please do my math homework

[Chiki]

Prove 1+1=2.

[Darros]

let 1 = x

x + x = 2x

As stated before, x = 1, so 2x must equal 2

2x = 2(1)

2x = 2

We stated earlier that x + x = 2x

x + x = 2

As stated before, x = 1, so 1 + 1 = 2

[Chiki]

That's middle school algebra proof lol

[Darros]

It didn't say prove using a specific method though! D:

I refuse to use induction I hate induction it is the very evil. Also can you even solve this with induction? I don't think so lol

[Freohr Datia]

Lol you said prove it and nothing else you goof xb

[Zerker]

Hold up a finger in one hand.

Hold up another in the opposite hand.

Move them together.

DONE HERE

[Esau of Isaac]

Prove 1+1=2.

1+1=2.

Phew. Someone get me a towel that was hard work.

[Elieson]

1+1=2

subtract 1 from both sides of the equation

1=1

Again

0=0

Wait I just broke it.

[BBM]

Serious answer because I'm bored: you can't actually prove that x + x = 2x without using 1 + 1 = 2.

x + x = 2x only because:

x + x = x(1) + x(1) (unitary property)

x + x = x(1 + 1) (distributive property)

x + x = 2x

There's no way to "prove" that 1 + 1 = 2; that's just how the number system was defined.

[OrangeCrush980]

Use the rule of addition

[Chiki]

Serious answer because I'm bored: you can't actually prove that x + x = 2x without using 1 + 1 = 2.

x + x = 2x only because:

x + x = x(1) + x(1) (unitary property)

x + x = x(1 + 1) (distributive property)

x + x = 2x

There's no way to "prove" that 1 + 1 = 2; that's just how the number system was defined.

Yes there is. :< in a book called Prinicipia Mathematica a man called Russell took 300 pages to prove it.

[LeThiAnh]

Yes there is. :< in a book called Prinicipia Mathematica a man called Russell took 300 pages to prove it.

Math: You gotta expect silly people to make a short proof extremely long.

Next thing you know, they prove that 1+1=0 is true. ....Wait.

[Fruity Insanity]

You have one cookie.

You get one more cookie.

Now you have zero cookies.

...Don't look at me like that! I didn't eat them! Nope, not at all.

[peener weener]

the simpler it seems, the harder it is to actually prove

usually

[Darros]

Math: You gotta expect silly people to make a short proof extremely long.

Next thing you know, they prove that 1+1=0 is true. ....Wait.

Silly, everyone knows 1 + 1 = 10

[Mikethfc]

Maths

: You gotta expect silly people to make a short proof extremely long.

Next thing you know, they prove that 1+1=0 is true. ....Wait.

Well, if you're working in modulo 2 then yes.

Yes there is. :< in a book called Prinicipia Mathematica a man called Russell took 300 pages to prove it.

Edited April 19, 2013 by Mikethfc

[BBM]

It's sort of a dumb proof though, because it still depends on the definition of two.

[Chiki]

Math: You gotta expect silly people to make a short proof extremely long.

Next thing you know, they prove that 1+1=0 is true. ....Wait.

You think x + x = 2 is proof that 1 + 1 = 2?

[Shin]

Silly, everyone knows 1 + 1 = 10

Fool! It's really 11! No wonder you're so bad at maths!

[Jaybee]

GODDAMN

[Darros]

Fool! It's really 11! No wonder you're so bad at maths!

But I was using the magical BINARY system.

[Narga_Rocks]

Is this a serious question you were asked for homework? How do they expect you to prove something like that? It's only true because we have defined the number system to be linear with 0, 1, 2, 3, 4, etc being the values for equivalent distances and addition to be combining two values in such a way as to start at one spot of the number system and move right or left a certain number of "spots" based on the value of the other number you are adding. Or alternatively, taking the value of a + b as the value of a and the value of b lumped together and then count up the number system until you reach the answer. Thus if I have an apple each in my left and right hands (1+1) and I throw them into the same pile, I can now count that I have 2 apples because we've defined the number system that way.

Are they looking for pages of proof of 1+1=2 or something? It sounds a lot like asking to prove that green is green when it's only green because we decided to name whatever we see with that wavelength green.

[Redwall]

I think he made the topic as a joke of sorts since another user had made a thread about an actual homework problem.

But Olwen is serious about the proof: http://en.wikipedia.org/wiki/Principia_Mathematica#Quotations

Edited April 20, 2013 by Redwall

[Narga_Rocks]

I think he made the topic as a joke of sorts since another user had made a thread about an actual homework problem.

But Olwen is serious about the proof: http://en.wikipedia.org/wiki/Principia_Mathematica#Quotations

So it is, basically, by definition 1+1=2.

[Chiki]

By definition, a successor of a number is a number. So the successor of 0 is one, the double successor of 0 is 2, and so on.

Also by definition, a number plus zero is itself.

That's where the definitions end, and 1+1=2 isn't by definition true. If you take the above axioms you'll find that 1+1 and 2 are both the double successors of 0, which proves it. You can prove any addition and subtraction and multiplication this way.