doclkk wrote:Hah sorry buddy, in case you were referring to me, i hate to say that im not from northern cal... but you were at least right about the confused part.mike22629 wrote: But again, right now - i'm way more confused and it seems that another northern california person is too.
Is there nobody here who can explain what this problem is really asking?
Absolute Value
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Svedankae
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mike22629
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Okay, I will try one more time, and if it does not work, just ask Ian. Absolute value DOES measure distance
So for example
l5l = distance from 5 to 0
l-5l = distance from -5 to 0
BUT
when TWO terms are inside of an absolute value sign, they must be subtracted from one another to find the distance between them.
SO
lx+yl = 6, that is NOT the distance inbetween x and y because they are being added. This is the distance of x from 0 PLUS the distance of y from 0.
Look at it visually
Say x = 4, y =2
----------------------0---------y-----------------
----------------------0--------------------------------x---
So the total distance is both of these lines added together
----------------------0-----------------------------------------------(x+y)
But the distance between x and y is 2, therefore lx+yl does not equal distance between x and y, it equals the distance between x and NEGATIVE y
NOW
If you flip either y or x as negative..
--------y-------------0------------------------------------x
You can see that the distance between x and y is actually equal to lx+yl because even though they are not at the same points, the distance is the same.
So for example
l5l = distance from 5 to 0
l-5l = distance from -5 to 0
BUT
when TWO terms are inside of an absolute value sign, they must be subtracted from one another to find the distance between them.
SO
lx+yl = 6, that is NOT the distance inbetween x and y because they are being added. This is the distance of x from 0 PLUS the distance of y from 0.
Look at it visually
Say x = 4, y =2
----------------------0---------y-----------------
----------------------0--------------------------------x---
So the total distance is both of these lines added together
----------------------0-----------------------------------------------(x+y)
But the distance between x and y is 2, therefore lx+yl does not equal distance between x and y, it equals the distance between x and NEGATIVE y
NOW
If you flip either y or x as negative..
--------y-------------0------------------------------------x
You can see that the distance between x and y is actually equal to lx+yl because even though they are not at the same points, the distance is the same.
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doclkk
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I got it nowmike22629 wrote:Okay, I will try one more time, and if it does not work, just ask Ian. Absolute value DOES measure distance
So for example
l5l = distance from 5 to 0
l-5l = distance from -5 to 0
BUT
when TWO terms are inside of an absolute value sign, they must be subtracted from one another to find the distance between them.
SO
lx+yl = 6, that is NOT the distance inbetween x and y because they are being added. This is the distance of x from 0 PLUS the distance of y from 0.
Look at it visually
Say x = 4, y =2
----------------------0---------y-----------------
----------------------0--------------------------------x---
So the total distance is both of these lines added together
----------------------0-----------------------------------------------(x+y)
But the distance between x and y is 2, therefore lx+yl does not equal distance between x and y, it equals the distance between x and NEGATIVE y
NOW
If you flip either y or x as negative..
--------y-------------0------------------------------------x
You can see that the distance between x and y is actually equal to lx+yl because even though they are not at the same points, the distance is the same.
So distance of X from 0 and Distance of Y from 0. Sum the distances.
Got it. Very clear explanation. =)
Sorry about the trouble, I went to public school. =)
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Svedankae
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I want to thank you and everyone else who has answered in this thread. unfortunately after reading it over and over again, i still havent quite figured it out. i always thought of me as having a very solid math background (i come from germany and we kinda take math seriuoslymike22629 wrote:Okay, I will try one more time, and if it does not work, just ask Ian. Absolute value DOES measure distance
So for example
l5l = distance from 5 to 0
l-5l = distance from -5 to 0
BUT
when TWO terms are inside of an absolute value sign, they must be subtracted from one another to find the distance between them.
SO
lx+yl = 6, that is NOT the distance inbetween x and y because they are being added. This is the distance of x from 0 PLUS the distance of y from 0.
Look at it visually
Say x = 4, y =2
----------------------0---------y-----------------
----------------------0--------------------------------x---
So the total distance is both of these lines added together
----------------------0-----------------------------------------------(x+y)
But the distance between x and y is 2, therefore lx+yl does not equal distance between x and y, it equals the distance between x and NEGATIVE y
NOW
If you flip either y or x as negative..
--------y-------------0------------------------------------x
You can see that the distance between x and y is actually equal to lx+yl because even though they are not at the same points, the distance is the same.
) and i also understand the idea of absolute value, but somehow this question is just not clicking. i think the main problem is that i dont really see the sense in this questioni would be extremely grateful if someone would add me on skype and maybe explain it to me via a phone call.. my nick is mostawesomect
thanks!
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lunarpower
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i'll try to make this simpler.
the ABSOLUTE VALUE OF A DIFFERENCE represents distance.
absolute values of other things don't.
therefore, if you can express the absolute value as | THIS - THAT |, where THIS and THAT are two quantities, then it's a distance between THIS and THAT.
here you go:
|x + y|
this does NOT have the above form, so, right now, it doesn't represent a distance at all.
BUT
you can rewrite it in any of the following three forms:
|x - (-y)| --> therefore it's the distance between x and (-y)
|y - (-x)| --> therefore it's the distance between y and (-x)
|(x+y) - 0| --> therefore it's the distance between (x+y) and 0
(nb: none of these 3 rewrites has anything to do with absolute value craziness; all three of x - (-y), y - (-x), and (x+y) - 0 can readily be seen to be equal to x + y. instead, the issue is "how do i write x + y as a DIFFERENCE?" because only DIFFERENCES, not sums, represent distances in this context.)
it has nothing to do with the distance between x and y, since you can't express it with |x - y|.
the ABSOLUTE VALUE OF A DIFFERENCE represents distance.
absolute values of other things don't.
therefore, if you can express the absolute value as | THIS - THAT |, where THIS and THAT are two quantities, then it's a distance between THIS and THAT.
here you go:
|x + y|
this does NOT have the above form, so, right now, it doesn't represent a distance at all.
BUT
you can rewrite it in any of the following three forms:
|x - (-y)| --> therefore it's the distance between x and (-y)
|y - (-x)| --> therefore it's the distance between y and (-x)
|(x+y) - 0| --> therefore it's the distance between (x+y) and 0
(nb: none of these 3 rewrites has anything to do with absolute value craziness; all three of x - (-y), y - (-x), and (x+y) - 0 can readily be seen to be equal to x + y. instead, the issue is "how do i write x + y as a DIFFERENCE?" because only DIFFERENCES, not sums, represent distances in this context.)
it has nothing to do with the distance between x and y, since you can't express it with |x - y|.
Ron has been teaching various standardized tests for 20 years.
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Pueden hacerle preguntas a Ron en castellano
Potete chiedere domande a Ron in italiano
On peut poser des questions à Ron en français
Voit esittää kysymyksiä Ron:lle myös suomeksi
--
Quand on se sent bien dans un vêtement, tout peut arriver. Un bon vêtement, c'est un passeport pour le bonheur.
Yves Saint-Laurent
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Learn more about ron
i am confuse too!!
why can't you just do this x + |y| = 6.
since Y is negative, you just put absolute value on Y.
and are you saying this is a fact?
|x| + |y| = |x + y| but i always thought when you put absolute values, it is like this
|x +y| = -x-y or x + y but Y is negative, so it doesnt make sense
why can't you just do this x + |y| = 6.
since Y is negative, you just put absolute value on Y.
and are you saying this is a fact?
|x| + |y| = |x + y| but i always thought when you put absolute values, it is like this
|x +y| = -x-y or x + y but Y is negative, so it doesnt make sense
