Math problem

>>7662724
think about what numbers are divisible by 3 and their relation to each other.

By way of contradiction, I'd wager

>>7662724

Given an integer X, we can consider its remainder when divided by 3. This remainder can only be 0, 1, or 2. That is, there exists an integer k such that X = 3k, X = 3k + 1, or X = 3k + 2.

Case 1: X = 3k

Then X is divisible by 3.

Case 2: X = 3k + 1

Then X + 2 = 3k + 3 = 3 (k + 1) is divisible by 3, as desired.

Case 3: X = 3k + 2

Then X + 4 = 3k + 6 = 3 (k + 2) is divisible by 3, as desired.

>>7662728
OP here
what you mean by contradiction? not english native :)

>>7662729
got it, thanks :D

>>7662730
Use a number that isn't a multiple of 3 to prove your point.

>>7662724
ins't it a trivial question?

What is [math]\sqrt{Love}[/math].
Bby don't hurt me.
Don't hurt me.
No more.

>>7662756

[math] O^{O^{O^{O^{O^{O^{O^{O^{O}}}}}}}} , O^{O^{O^{O^{O^{O}}}}} , A^{A} [/math]

>>7662724

For any integer X, X+2, or X+4 is always divisible by 3.

Counter example: 0
X = 0 X+2 = 2 X+4 = 4

Statement is incorrect.
QED

>>7662729
Literal retard.

You better learn to phrase your questions, OP.

3 numbers from all 3 congruence classes modulo 3.

QED

>>7662729
This is proof. Nice work anon.

>>7662782
You didn't negate your existential qualifier. Not the contrapositive. No proof. also not believing the remainder argument makes you bonus stupid. Stay away from maths.

>>7662782
Zero is divisible by every nonzero integer. Have fun in remedial math.

File: 94a.jpg (137KB, 432x360px) Image search: [Google]

137KB, 432x360px

>>7662782
>Statement is incorrect.
>QED
>0 is not divisible by 3
THE MORE YOU KNOW

>>7662804
>You didn't negate your existential qualifier. Not the contrapositive. No proof.
The fuck are you talking about. A counterexample is a counter proof. Because P implies Q is disproved by any not Q using any P. His problem is that his counterexample is wrong.

>>7662804
>Not the contrapositive

The contrapositive doesn't have anything to do with what he was trying to show

This is really easy by using induction anon

>>7662724
Math PhD here, just try them all.
Don't believe >>7662729, using letters in math is bad form.

[math]x(x+2)(x+4) = x(x+1)(x+2)+ 3 x (x+2)[/math]

>>7662730
Look up "modular arithmetic."


Hint: X+4 is the same as X+1 (mod 3).