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2008-10-17 22:04:36

Scorpion0x17: can detect anyone's visible post count...; +691|7218|Cambridge (UK)

mcminty wrote:
Scorpion0x17 wrote:
mcminty wrote:

also commonly known as √2...
Exactly.
How can you say "exactly" to that??

If I had written √3-1 as meaning the "square root of 3-minus-1", then I would have written √2. So I must have meant "the square root of 3, minus 1".

How is that confusing at all?

Yeah, but they're also just symbols - if it had've been √2 you meant then you may also have been leaving the -1 separate from the 3 to make it clear how you were manipulating the equation.

And that style of √, could lead to confusion - what's √3-a ? is it "the square root of 3, minus a"? or "the square root of 3-minus-a"?

2008-10-17 22:34:27

mcminty: Moderating your content for the Australian Govt.; +879|7173|Sydney, Australia

Scorpion0x17 wrote:
mcminty wrote:
Scorpion0x17 wrote:
Exactly.
How can you say "exactly" to that??

If I had written √3-1 as meaning the "square root of 3-minus-1", then I would have written √2. So I must have meant "the square root of 3, minus 1".

How is that confusing at all?
Yeah, but they're also just symbols - if it had've been √2 you meant then you may also have been leaving the -1 separate from the 3 to make it clear how you were manipulating the equation.

And that style of √, could lead to confusion - what's √3-a ? is it "the square root of 3, minus a"? or "the square root of 3-minus-a"?

...are you... retarded? Seriously.

For the first point,

It was clear how I manipulated the equation, as it was done via the distributive law. Even if one doesn't call it that, I was still taking out the "common factor" of x.

And on the second point:

1. √a - b is the square root of a, minus b

2. √(a-b) is the square root of a-minus-b.

$https://upload.wikimedia.org/math/b/f/3/bf3ad54d060ca456987fdccfe6705c7b.png$ is the same as √x

2008-10-17 22:39:21

VicktorVauhn: Member; +319|6844|Southern California

mcminty wrote:
Scorpion0x17 wrote:
mcminty wrote:

also commonly known as √2...
Exactly.
How can you say "exactly" to that??

If I had written √3-1 as meaning the "square root of 3-minus-1", then I would have written √2. So I must have meant "the square root of 3, minus 1".

How is that confusing at all?

Some times when people do math they show different steps.

However you are correct on the grouping... then again I was correct in the way I wrote it and people still complained about it being confusing, and that is why you are correcting me. No real point in correcting something that is confusing to one person with something else that's just as confusing.

aj0404 wrote:
i think we should stop arguing about math...

You don't have to be here...

2008-10-17 22:41:44

mcminty: Moderating your content for the Australian Govt.; +879|7173|Sydney, Australia

VicktorVauhn wrote:
mcminty wrote:
Scorpion0x17 wrote:
Exactly.
How can you say "exactly" to that??

If I had written √3-1 as meaning the "square root of 3-minus-1", then I would have written √2. So I must have meant "the square root of 3, minus 1".

How is that confusing at all?
Some times when people do math they show different steps.

However you are correct on the grouping... then again I was correct in the way I wrote it and people still complained about it being confusing, and that is why you are correcting me. No real point in correcting something that is confusing to one person with something else that's just as confusing.

Hmm.. true I guess.

VicktorVauhn wrote:
aj0404 wrote:
i think we should stop arguing about math...
You don't have to be here...

QFE.

2008-10-17 23:20:02

nukchebi0: Пушкин, наше всё; +387|6776|New Haven, CT

VicktorVauhn wrote:
nukchebi0 wrote:
I am sorry you are confused by parenthesis, when you see a number on the outside of them and an equation on the inside it means you multiply each term of the equation on the inside by the number on the outside.
Wow, thanks for the math lesson, professor. I'm struggling through algebra this year, and your brilliance just shines through the cloud that is the complicated concepts. Really, stop being so arrogant. You aren't smarter than anyone else, even if your misguided mind wants it to be so. I know how to do math; don't be so ignorant. It just makes you look pathetic and desperate for attention.
I am definitely smarter then some in here, lol... but that doesn't mean much, your smarter then some in here too... Its not like we are all exactly equal and I am pretty sure I am not at the bottom. Not that I ever mentioned anything about being smarter then others in here.

Sorry, that isn't exactly what I meant to convey. I should have clarified better.

Honestly though if you understand and already knew what I explained then what I wrote really isn't difficult to read, If you are having trouble with it you made a mistake, or don't understand. If you don't understand I explained, if you made a mistake... hell it happens, but that is your mistake and nothing to do with my statement.

No, not really. The parantheses were hard to see.

2008-10-18 00:22:03

VicktorVauhn: Member; +319|6844|Southern California

nukchebi0 wrote:
No, not really. The parantheses were hard to see.

Uhh? I could type them in bold? They are there, and its not like I did a bad job hand writing them, or I didn't press hard enough and they were faint... They are typed out in standard font right there... I don't really know what to say to that one man.

2008-10-18 00:28:07

nukchebi0: Пушкин, наше всё; +387|6776|New Haven, CT

The proximity to the '*' drowned the first one out, and the second one was also hard to see next to the '1'. I was just saying, by my comment, that to someone looking over it, the parentheses were hard to initially see. My confusion was helped because of the fact that I never put a multiplication sign when I factor something out, even on the internet, so I assumed they weren't there after I didn't initially see them.

Last edited by nukchebi0 (2008-10-18 00:28:55)

2008-10-18 00:48:55

Poppa Bear: Member; +3|6697

So, i've got another problem for you to solve:
prove that the formula is true for every differentiable function f

Last edited by Poppa Bear (2008-10-19 02:05:35)

2008-10-18 01:30:48

nukchebi0: Пушкин, наше всё; +387|6776|New Haven, CT

How do you have to do it?

2008-10-18 01:31:36

rdx-fx: ...; +955|7043

For the OP

X = -5.4641

or

X= (-4) / (-1 + √3)

Hint: check it on your friendly neighborhood TI-89.
solve(3^.5*x=x-4, x)
"solve(" is under your F3 key menu

and, for Poppa Bear, a proof of the symmetric difference quotient

limh→0 [ƒ(x+h)-ƒ(x-h)]/(2h) = limh→0 {[ƒ(x+h)-ƒ(x)]-[ƒ(x-h)-ƒ(x)]}/(2h)
= ½limh→0 {[ƒ(x+h)-ƒ(x)]-[ƒ(x-h)-ƒ(x)]}/h
= ½limh→0 {[ƒ(x+h)-ƒ(x)]/h - [ƒ(x-h)-ƒ(x)]/h}
= ½limh→0 {[ƒ(x+h)-ƒ(x)]/h + [ƒ(x+(-h))-ƒ(x)]/(-h)}
= ½{limh→0 [ƒ(x+h)-ƒ(x)]/h + limh→0 [ƒ(x+(-h))-ƒ(x)]/(-h)}
= ½{2limh→0 [ƒ(x+h)-ƒ(x)]/h}
= limh→0 [ƒ(x+h)-ƒ(x)]/h

http://community.livejournal.com/mathproofs/973.html

2008-10-18 01:45:25

Poppa Bear: Member; +3|6697

thanks. I think i got the gist of it, even though it involves some methods i haven't learned yet

2008-10-18 01:51:43

rdx-fx: ...; +955|7043

Poppa Bear wrote:
thanks. I think i got the gist of it, even though it involves some methods i haven't learned yet

http://www.mecca.org/~halfacre/MATH/lesson7.htm explains it a little better

http://education.ti.com/html/t3_free_co … sson3.html goes into more detail about why it's useful

google for "Symmetric Difference Quotient" will tell you more than you ever wanted to know.

My Previous post was terse, as I mistakenly thought you were being a smartass by throwing a Calculus problem into an Algebra thread

2008-10-18 02:00:23

Poppa Bear: Member; +3|6697

thanks for the links. I HAVE googled, but i didn't know the correct english term for it
i''ve got yet another problem to solve so please bear with me, however, it isn't calculus this time (well, maybe)

give proof that the inequality is true for every real number x
I think I've managed to prove it myself, but I'm asking just to be sure.

Last edited by Poppa Bear (2008-10-18 02:35:33)

2008-10-18 02:07:07

nukchebi0: Пушкин, наше всё; +387|6776|New Haven, CT

I have a really, really, roundabout way doing this with calculus, but I'm sure that isn't what you were thinking. I could explain, though, if you wished.

Edit: This might be a general idea how do, not with calculus.

Take (1-x)⁸ and subtract 1-8x from it.
Set a new function equal to this.
If 1-8x is ever greater than (1-x)⁸, then the function will be less than zero.
Graph it/show the equation is never less than zero.
Proven.

Last edited by nukchebi0 (2008-10-18 02:13:43)

2008-10-18 02:28:47

VicktorVauhn: Member; +319|6844|Southern California

nukchebi0 wrote:
The proximity to the '*' drowned the first one out, and the second one was also hard to see next to the '1'. I was just saying, by my comment, that to someone looking over it, the parentheses were hard to initially see. My confusion was helped because of the fact that I never put a multiplication sign when I factor something out, even on the internet, so I assumed they weren't there after I didn't initially see them.

Well, again... That's simply your mistake... the * may not be needed but if you closely look at it its obvious what it means. They do get to be a jumble when typed out though.

Part of it is going from Ti-83 to Ti-89 to computer programs and what not I just throw shit like that in because why not? It has only taken a few wrong answers due to me not putting in enough parenthesis or multiplication signs (for example, when using the differential function on the Ti-89 3x doesn't work the same as 3*x) for me to just play it safe. I don't have the time or motivation to learn the rules each calculating device so I just put it in in a way where it cannot possibly be read incorrectly (with out operator error).

2008-10-18 02:34:09

nukchebi0: Пушкин, наше всё; +387|6776|New Haven, CT

My mistake, as you keep pointing out, could easily be made by other people, hence why your notation wasn't conducive to easily understanding.

Your rationale for why you did it is fine, though. I understand why.

2008-10-18 02:34:47

Poppa Bear: Member; +3|6697

nukchebi0 wrote:
I have a really, really, roundabout way doing this with calculus, but I'm sure that isn't what you were thinking. I could explain, though, if you wished.

Edit: This might be a general idea how do, not with calculus.

Take (1-x)⁸ and subtract 1-8x from it.
Set a new function equal to this.
If 1-8x is ever greater than (1-x)⁸, then the function will be less than zero.
Graph it/show the equation is never less than zero.
Proven.

Well, you're free to use calculus if you wish. I may have to change the assertion that the proof doesn't involve calculus, because that's how I think it's supposed to be proven. Btw, it's from the final math exam before we graduate from high school, a standardized test that every high school student in the country takes. So how you approach the problem shouldn't make any difference as long as it's correct

2008-10-18 03:01:29

nukchebi0: Пушкин, наше всё; +387|6776|New Haven, CT

Okay, it would involve finding where the two sides of the equation were equal, and the critical points of (1-x)⁸ (where the derivative is xero; essentially, where the graph turns around). Then, you would evaluate the definite integrals of each function's derivative on the intervals between the points you found above, and on some arbitrary number far on either side (example, simplified: you have them equal at 0 and 4, with a critical point at 2, so you evaluate on (-40, 0); (0,2); (2, 4); and (4, 40). Where the derivative of -- -8(1-x)⁷ -- is positive, you show that the definite integral is a greater value than for 1-8x's derivative -- -8 -- implying (1-x)⁸ gained more from the equal point and thus has a greater value. When -8(1-x)⁷ is negative, you show that the definite integral of it is a smaller value (keep in mind -5 is smaller than -2) than of -8, showing that (1-x)⁸ had to lose more value to reach the equal point, and corroborating the conclusion that it was higher.

This is really rough, and probably has some errors, but I was doing this without paper. It should give a general idea how you can use calculus to prove it, though.

Last edited by nukchebi0 (2008-10-18 03:01:51)

2008-10-18 03:31:19

VicktorVauhn: Member; +319|6844|Southern California

nukchebi0 wrote:
My mistake, as you keep pointing out.

BTW when I point out "your mistake" I don't mean it in a "you stupid twat" kinda way... We all certainly make our fair share, sifting through equations can be monotonous enough, and when they are typed out without the benefit of the proper symbols they can certainly become a cluster fuck very quickly... Just saying its sound as written and any mistake in interpreting it is the mistake of the reader (and not a mistake I am above making).

I can certainly see why (especially on something as insignificant as this) you can misread something like that as you glance over it... just backing that if you actually sit an look through it carefully piece by piece its nothing too confusing, and the problem is simple enough that with steps listed before and after it should be easy enough to follow.

2008-10-18 03:50:10

rdx-fx: ...; +955|7043

Poppa Bear wrote:
thanks for the links. I HAVE googled, but i didn't know the correct english term for it
i''ve got yet another problem to solve so please bear with me, however, it isn't calculus this time (well, maybe)

give proof that the inequality is true for every real number x
I think I've managed to prove it myself, but I'm asking just to be sure.

It looks like "Induction" using the "Bernoulli Inequality"

http://mathforum.org/library/drmath/view/51613.html

http://mathworld.wolfram.com/BernoulliInequality.html

http://en.wikipedia.org/wiki/Bernoulli_inequality

Try looking for "Principle of Mathematical Induction" and/or "Bernoulli Inequality"

2008-10-18 13:58:57

Scorpion0x17: can detect anyone's visible post count...; +691|7218|Cambridge (UK)

VicktorVauhn wrote:
mcminty wrote:
Scorpion0x17 wrote:

Exactly.
How can you say "exactly" to that??

If I had written √3-1 as meaning the "square root of 3-minus-1", then I would have written √2. So I must have meant "the square root of 3, minus 1".

How is that confusing at all?
Some times when people do math they show different steps.

However you are correct on the grouping... then again I was correct in the way I wrote it and people still complained about it being confusing, and that is why you are correcting me. No real point in correcting something that is confusing to one person with something else that's just as confusing.

Exactly.

McMint: I knew exactly what you meant, just as I knew exactly what Vicktor meant - but that's because I am math-literate.

The point I was making (maybe poorly) was that mathematical symbols are just that, symbols - with no inherent meaning - we, through learning the language of mathematics, learn to distinguish different, inherently ambiguous, combinations of abstract symbols and assign them each different concrete meanings.

Vicktor's approach and yours both said the same thing and were both equally ambiguous - it is only our math-literacy that disambiguates the meaning.

2008-10-18 15:50:31

Jenspm: penis; +1,716|7184|St. Andrews / Oslo

tbh,

√(3-1) = √2
√(3)-1 = √3 - 1
√3-1 = cunfusing.

imo, you should all get a formula editor for MS Word, and printscreen/upload images

https://static.bf2s.com/files/user/26774/flickricon.png

2008-10-18 16:42:15

VicktorVauhn: Member; +319|6844|Southern California

Jenspm wrote:
tbh,

√(3-1) = √2
√(3)-1 = √3 - 1
√3-1 = cunfusing.

imo, you should all get a formula editor for MS Word, and printscreen/upload images

IMO you should shut the hell up.

<3

(Always reminds me of my high school English teacher and talking about not using "in my opinion" because its so easily counter by the other person offering THEIR opinion...)

Really though, I don't type enough math on forums to worry about it. I was just giving a quick "simple" answer, and it happened to stem into a larger discussion.

Showing some one how to factor isn't really worth downloading more crap to my computer, opening word, taking screen shots, cropping them, then uploading them just so I can avoid writing sqrt(z).

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mcminty wrote:

Scorpion0x17 wrote:

mcminty wrote:

Scorpion0x17 wrote:

mcminty wrote:

Scorpion0x17 wrote:

mcminty wrote:

Scorpion0x17 wrote:

mcminty wrote:

aj0404 wrote:

VicktorVauhn wrote:

mcminty wrote:

Scorpion0x17 wrote:

VicktorVauhn wrote:

aj0404 wrote:

VicktorVauhn wrote:

nukchebi0 wrote:

nukchebi0 wrote:

Poppa Bear wrote:

nukchebi0 wrote:

nukchebi0 wrote:

nukchebi0 wrote:

Poppa Bear wrote:

VicktorVauhn wrote:

mcminty wrote:

Scorpion0x17 wrote:

Jenspm wrote:

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