wat is 1 + 1?

2.

This is the proof:
P1. 1 is in N.
P2. If x is in N, then its "successor" x' is in N.
P3. There is no x such that x' = 1.
P4. If x isn't 1, then there is a y in N such that y' = x.
P5. If S is a subset of N, 1 is in S, and the implication
(x in S => x' in S) holds, then S = N.

Then you have to define addition recursively:
Def: Let a and b be in N. If b = 1, then define a + b = a'
(using P1 and P2). If b isn't 1, then let c' = b, with c in N
(using P4), and define a + b = (a + c)'.

Then you have to define 2:
Def: 2 = 1'

2 is in N by P1, P2, and the definition of 2.

Theorem: 1 + 1 = 2

Proof: Use the first part of the definition of + with a = b = 1.
Then 1 + 1 = 1' = 2 Q.E.D.

2006-09-19 02:14:26 · answer #1 · answered by menezes_dean 2 · 0⤊ 0⤋

3

2006-09-19 06:20:56 · answer #2 · answered by tronic_hobbist 2 · 0⤊ 0⤋

It Can be anything according to the situation
In Mathematics 1 + 1 is equal to 2;
IF u take a One protein and one atom and if u add them.. then the answer will be One..
If u take One potive charge and add to one negetive charge then the answer will be Zero
And If your answer is 2 in chemistry then the chemist may think that the answer is close to 2 like u can not the find the particle position exctly...
IF u take an ecomomist......... 1 + 1 is not qual to 2 bit it is more then to or close to 2..
Like this it depends on the wy of thinking at the question

2006-09-19 04:25:50 · answer #3 · answered by ashu 1 · 0⤊ 0⤋

In simple arithmetic

1+1 = 2.

In binary (base 2) system:
1 + 1 = 10

In Logical Operations, whenever "+" represents the "AND" operator:
1 + 1 = 1.

2006-09-19 04:21:08 · answer #4 · answered by K Sengupta 4 · 1⤊ 0⤋

In simple mathematics, it would be 2.

In binary operations, it would be 10.

In Yahoo! Answers, that would be 5 points to be wasted for asking such an easy question.

2006-09-19 07:50:52 · answer #5 · answered by whitelighter 4 · 0⤊ 0⤋

2?

2006-09-19 04:16:47 · answer #6 · answered by CeeCee 2 · 1⤊ 0⤋

if u start counting decimal number system.
0 - first
1 - second
2 - third
.
.
.
so on
so 1 + 1 is nothing but basic counting process one by one. so it would be third Decimal number. so the answer must be "2".

http://www.humonline.com/members/forum/pub_loginform.aspx

2006-09-19 04:49:08 · answer #7 · answered by Sant 2 · 0⤊ 0⤋

'1+1' is part of an equation. the addends.

2006-09-19 04:28:24 · answer #8 · answered by Laika 4 · 0⤊ 0⤋

i think ur a kid, maybe ur mom is teachig how to use yahoo answers not math.....cool.....oh forgot to answer ,the answer is 2

and 4+4=8 and 2x2=4 u must be the luckiest kid to go to y.a. (if ur a KID).

well u can choose me as best answers... :)

2006-09-19 05:30:47 · answer #9 · answered by I'll help you_now 3 · 0⤊ 0⤋

2, but how do you know that's so?

Anyone who answers "because my teacher told me" has given the wrong answer.

2006-09-19 04:17:58 · answer #10 · answered by Anonymous · 1⤊ 0⤋

19 answers