-1 x -1 = +1 is not evil math

[Lou]

I read an article the other day from this guy who claimed that -1 x -1 = +1 is 'evil' math. I understand where he is coming from with that statement, but -1 x -1 = +1 is not an arbitrary convention adopted by mathematicians to make everything fit in nicely. Calling it a 'rule' is a bit misleading too. There is a lot of smart people on this forum who *understand* why -1 x -1 = +1, so, if you are among this group of people, you need to read no further. But if you are curious, highlight to read:

Spoiler

Observe the following:
-1 x 0 = 0

Now -1 + 1 = 0. Replace the 0 on the left side of the previous expression by -1 + 1:
-1 x (-1 + 1) = 0

Now expand that expression:
(-1 x -1 ) + (-1 x 1) = 0

Which simplifies to:
(-1 x -1) + (-1) = 0

Which is equivalent to:
-1 x -1 = 1

Evil math, right you moron?

 

[Shamrock]

All I know is that 3 = white shoe, and you are an idiot if you don't believe it.

 

[Ikerous]

-1 x 0 = 0

I disagree. Prove it.

 

[Lou]

I disagree. Prove it.

a x 0 = 0 for all real numbers a.
-1 is a real number
therefore -1 x 0 = 0.

 

[Nat Turner]

a x 0 = 0 for all real numbers a.
-1 is a real number
therefore -1 x 0 = 0.

lol correct. '0' is the identity element for the multiplication operator in the set of real numbers, IIRC.

 

[OCybrManO]

I disagree. Prove it.

... and we all know Google is never wrong.

 

[Ikerous]

a x 0 = 0 for all real numbers a.

I was asking you to prove that...

(It's the reason why your proof is false. -1 x -1 != 1)

 

[Nat Turner]

I was asking you to prove that...

(It's the reason why your proof is false. -1 x -1 != 1)

lol you don't have to prove it. It's one of the definitions you start with for the real number set. You prove other things with that.

 

[Ikerous]

but -1 x -1 = +1 is not an arbitrary convention adopted by mathematicians to make everything fit in nicely. Calling it a 'rule' is a bit misleading too. There is a lot of smart people on this forum who *understand* why -1 x -1 = +1

I'm simply asking he applies the same logic to C x 0. Theres no reason to think his proof is valid if he cant prove c x 0 = 0 is anything less than just something made up by jews.

 

[Nat Turner]

I was asking you to prove that...

(It's the reason why your proof is false. -1 x -1 != 1)

lol you don't have to prove it. It's one of the definitions you start with for defining a group in the real number set under the * operator. Basically if a * 0 isn't a, then you can't prove anything.

edit: terminology

 

[Lou]

I was asking you to prove that...

(It's the reason why your proof is false. -1 x -1 != 1)

Nah. Follow this line of thought:

a x 0
= a x (1 + -1)
= (a x 1) + (a x -1)
= a + -a
= 0

Therefore a x 0 = 0

 

[Ikerous]

You must realize i was being ironic...?
Trying to show you the insanity in your own remarks by stating something almost exactly alike that sounds insane...

Maybe i only make sense to myself :/

 

[TheSomeone]

What ikerous is trying to say is: proving 1 x 0 = 0 is just as stupidly pointless as proving -1 x -1 = 1.

 

[15357]

We learned that in 6th grade....

 

[Nat Turner]

We learned that in 6th grade....

Yeah, but you didn't learn the proof of it.

 

[Ikerous]

We learned that in 6th grade....

What ikerous is trying to say is: proving 1 x 0 = 0 is just as stupidly pointless as proving -1 x -1 = 1.

I love you guys <3

Yeah, but you didn't learn the proof of it.

lol you don't have to prove it. It's one of the definitions you start with for defining a group in the real number set

Get it?

 

[Nat Turner]

Ikerous:

I was saying you don't have to prove 1 x 0 = 0 (not -1 x -1 = 1). I may actually be wrong though... hehe.

 

[Ikerous]

Ikerous:

I was saying you don't have to prove 1 x 0 = 0 (not -1 x -1 = 1).

lmao ::slaps myself on the forehead::

Just for the sake of our marriage, tell me you understand the irony

 

[TheSomeone]

You guys are married? Can I get in on this?

 

[Lou]

... and we all know Google is never wrong.

Calculator incorporated with the search engine? Google is a bag full of surprises.
Edit: Yahoo also does it...

 

[15357]

Yeah, but you didn't learn the proof of it.

Uh, we did.


We were all like: "WTF? Why is there even proof for that?"

 

[sinkoman]

I read an article the other day from this guy who claimed that -1 x -1 = +1 is 'evil' math. I understand where he is coming from with that statement, but -1 x -1 = +1 is not an arbitrary convention adopted by mathematicians to make everything fit in nicely. Calling it a 'rule' is a bit misleading too. There is a lot of smart people on this forum who *understand* why -1 x -1 = +1, so, if you are among this group of people, you need to read no further. But if you are curious, highlight to read:

Spoiler

Observe the following:
-1 x 0 = 0

Now -1 + 1 = 0. Replace the 0 on the left side of the previous expression by -1 + 1:
-1 x (-1 + 1) = 0

Now expand that expression:
(-1 x -1 ) + (-1 x 1) = 0

Which simplifies to:
(-1 x -1) + (-1) = 0

Which is equivalent to:
-1 x -1 = 1

Evil math, right you moron?

This is gradeschool math.

Negative times negative makes positive.

 

[Nat Turner]

lmao ::slaps myself on the forehead::

Just for the sake of our marriage, tell me you understand the irony

lol I understand the irony. The proofs for these kinds of things seem pointless, but apparently they're really important for mathematicians.

And yes our marriage is saved!

 

[Nat Turner]

Uh, we did.


We were all like: "WTF? Why is there even proof for that?"

I didn't know they taught proofs for that in sixth grade. Funneh.

 

[Lou]

Uh, we did.


We were all like: "WTF? Why is there even proof for that?"

Did you finish your math homework, or do you need more help?

http://www.halflife2.net/forums/showthread.php?t=99447

 

[15357]

I didn't know they taught proofs for that in sixth grade. Funneh.

You don't live in Korea, right?

We have this ****ed up education system in which everything is counted on your grades from 7th grade, and the high school you go to changes your whole future.

-------------------------------------------------
That was my old homework. I just typed it wrongly.

 

[Nat Turner]

You don't live in Korea, right?

Nope, I live in Massachusetts.

 

[dream431ca]

Uh Oh! Another math quiz thread!! -1 x -1 = +1. If you multiply 2 negatives you get a positive. How difficult is that to understand..grade 4 math people...come on.

 

[DEATH eVADER]

I was asking you to prove that...

(It's the reason why your proof is false. -1 x -1 != 1)

Its the same as saying

-1 x -1 = (--1)
but both of those contains a negative integer, so it would work out at this
--1 = 1

Its the same as saying, Minus a negative would make it a positive (reversal)
It works on all numbers

-2 x -2

-2 x -2 = 4
same as
-2 x -2 = (--4)
therefore
--4 = 4

-2 x -3

-2 x -3 = 6
same as
-2 x-3 = --6
therefore
--6 = 6

The only way you will be able to get a negative outcome would be to multiply three numbers (or odd amount of numbers, i.e. 3, 6, 9)

-2 x -3 x -4

-2 x -3 x -4 = -24
same as
-2 x -3 x -4 = ---24
Minus a negative would be elimated (only pairs of negatives can do this)
therefore
---24 = -24

Pairs of negative cancell each other out, so you could say

Even amount of negative units form a positive
--2 = 2
----4 = --4 = 4

Odd amount of negative units form a negative
---2 = -2
-----4 = ---4 = -4

 

[Beerdude26]

Calculator incorporated with the search engine? Google is a bag full of surprises.
Edit: Yahoo also does it...

You don't know half of Google's functions
http://www.google.com/intl/eng/help/operators.html

FTW \0/

 

[Danimal]

Negative x Negative = Positive
Positive x Negative = Negative
Positive x Positive = Positive

Kapiesh?

 

[clarky003]

Q33 NY

is the flight number for one of the planes that went into the twin towers, apply wingdings font to it and it is weirder than any math's.

 

[The Brick]

If you think about it, I don't see how this should make sense.

 

[Cormeh]

You mean, if I owe you two apples, that gains me one apple? :O

 

[DEATH eVADER]

If you think about it, I don't see how this should make sense.

Because Multiply works differently to Addition, Multiply has different mechanics. The reason why it doesn't look right is because you contradicting your earlier statement
think of it as,
"I sold(-) One apple, but I didn't want to(-), so I bought(x)it back"
or
"I sold(-) one apple, but I bought(x) it back because I didn't want to sell it in the first place(-)"

-1 x -1 = 1
-1 + -1 = -2

 

[Ravioli]

-1 x 0 = 0

uhm...isnt that equal to -1 ?

I mean, 3 x 0 = 3, and 8257 x 0 = 8257

So why wouldnt -1 x 0 = 0 be: -1 x 0 = -1 ?

 

[Danimal]

Anything multiplied by zero will have an answer of zero.

 

[DEATH eVADER]

I mean, 3 x 0 = 3, and 8257 x 0 = 8257

No, because 3 x 1 = 3, and 8257 x 1 = 8257 (Notice the magic number is one)

So why wouldnt -1 x 0 = 0 be: -1 x 0 = -1 ?

Because -1 x 1 = -1

In multiplication mechanics:
ex.

4 x 0 = (I have four lots of nothing)

0 x 4 = (I have no lots of four)

or

4 x 1 = (I have four lots of one's)

1 x 4 = (I have one lot of four)

 

[15357]

If you can answer 2 * 4^2 * (-4)^0.5 with using only numbers and equation thingys(!,%,^,*,/,*,-,+), then i'll give you 10 thousand dollars.

 

[Murray]

You shouldn't proove something, using the rules of what you proove.