Something that you just have to know

[seeker372011 (Narayan)]

found this in another forum:



mathematical proof that 1+1=2

http://mathforum.org/library/drmath/view/51551.html

[[1ponders] (Paul)]

I think some maths people need to get a life.

[toetoe (Peter)]

Thank god for that, my head has been hurting so much trying to work that out.

[ballaratdragons (Ken)]

And here I was all this time thinking 1 + 1 = 11

Silly me!

[ving (David)]

nah 1+1=3... ask any parent

[Itchy]

Thanks Seeker,

Brings back memories. I studied the successor function in my second year of my maths degree. It was actually quite satisfying to realize that someone could actually prove 1+1=2. This, in reality, gives us a firm foundation for the rest of our mathematics.

I know I know, I need a life!

Originally Posted by seeker372011

found this in another forum:



mathematical proof that 1+1=2

http://mathforum.org/library/drmath/view/51551.html

[janoskiss (Steve H)]

Stop that! It's silly.

Proof? No. Definition? Yes.

If b = 1, then define a + b = a'
Then you have to define 2:
Def: 2 = 1'

[Itchy]

Originally Posted by janoskiss

Stop that! It's silly.

Proof? No. Definition? Yes.

No. It is a proof. The definition you quote is that when you apply the successor function to 1 (1') you get 2. Using this definition and the definition of addition (also defined in the proof), what is presented is a proof.

This proof has been around for many years. I first came across it in 1977. It is a valid and accepted piece of mathematics, peer reviewed and published. It is actually a very important piece of work, providing the underpinnings of our number system. It was part of a course called the Foundations of Mathematics. It took our lecturer 3 two hour lectures to get to this proof.

Not silly at all.

Cheers

Tony Hitchcock BMath (Newcastle)

[ballaratdragons (Ken)]

Um, if I hold 1 finger up, then hold another 1 finger up, I am holding up 2 fingers.

Makes sense to me!

[seeker372011 (Narayan)]

isnt maths fun

[janoskiss (Steve H)]

Originally Posted by seeker372011

isnt maths fun

My theory about that is that it depends on your grade 4-5 maths teacher(s). Mine were great and as a little kid I was just so impressed how a simple and absolutely brainless manipulation of symbols could so easily answer seemingly complicated questions. Most people think that math is horribly difficult. But it is the easiest of all subjects. (Unlike history & literature for example.) No ambiguities and almost nothing to remember.

With math, you define the world to which your statements apply. It is pure abstraction. Pure creation of the human mind. The amazing thing is that the real world has parallels with the pure-math fantasy world, so much so that we are able to make mind-blowingly accurate predictions about the real world by combining math with direct observation. And this allows us to do amazing things like put man on Moon, make precise GOTO scopes and many other impressive things...