Cmdr. Cracken

01-30-2001, 06:51 PM

Keyan, or any other math geniuses, can you help me under stand functions and function notation? (Not in C++, ADV. ALGEBRA)

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Cmdr. Cracken

01-30-2001, 06:51 PM

Keyan, or any other math geniuses, can you help me under stand functions and function notation? (Not in C++, ADV. ALGEBRA)

JR2000Z

01-30-2001, 07:02 PM

Im sure we can.

Admiral

01-30-2001, 07:09 PM

a function is anything that passes the the y axis only once.

for instance

f(x)=2x(sq)+x

if you give a number say 4 you get.

2(4)(sq)+4=36

------------------

"Dulce bellum inexpertis."

(Sweet is war to those who have never experinced it.) Roman Proverb

for instance

f(x)=2x(sq)+x

if you give a number say 4 you get.

2(4)(sq)+4=36

------------------

"Dulce bellum inexpertis."

(Sweet is war to those who have never experinced it.) Roman Proverb

Rogue Nine

01-30-2001, 07:09 PM

You could show them to us, dunno if I personally will be of any help...

Keyan Farlander

01-30-2001, 07:44 PM

Originally posted by Admiral:

a function is anything that passes the the y axis only once.

NO!!! That is not true at all! It is true that if it does pass the y axis more than once, it is not a function, but it needs much more to actually be a function.

A function is a mapping from one set of values to another. The key is that no element from the domain ("mappers") can map to more than one element of the range ("mappees"). Now, two or more elements of the domain can map to the same member of the range - that makes no difference. So if you think about it in terms of the graph, no two points can be on top of each other. The graph cannot cross ANY vertical line more than once.

a function is anything that passes the the y axis only once.

NO!!! That is not true at all! It is true that if it does pass the y axis more than once, it is not a function, but it needs much more to actually be a function.

A function is a mapping from one set of values to another. The key is that no element from the domain ("mappers") can map to more than one element of the range ("mappees"). Now, two or more elements of the domain can map to the same member of the range - that makes no difference. So if you think about it in terms of the graph, no two points can be on top of each other. The graph cannot cross ANY vertical line more than once.

Rogue Nine

01-30-2001, 07:48 PM

The great and amazing Keyan has spoken! Be stupefied!

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Love people. Use things. Not vice versa.

XWA's Resident Finance Manager

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Love people. Use things. Not vice versa.

XWA's Resident Finance Manager

Keyan Farlander

01-30-2001, 08:38 PM

You know it, baby. I may be a loser in almost everything else, but I know my math.

Darth Sceltor

01-30-2001, 08:43 PM

My head hurts.

Psycho Tycho

01-30-2001, 10:05 PM

Yeccch, math. Forget about math. Yeccch, school.

Rogue Nine

01-30-2001, 10:11 PM

Just giving him the props he deserves.

Zoom Rabbit

01-30-2001, 10:51 PM

I function as a biological perambulation unit!

Admiral

01-30-2001, 11:03 PM

Your right Keyan. I haven't used functions for over a year so...must have forgotten some. we need to chat some math some time.

Cracken if you can post some problems I could help some more.

------------------

"Dulce bellum inexpertis."

(Sweet is war to those who have never experinced it.) Roman Proverb

Cracken if you can post some problems I could help some more.

------------------

"Dulce bellum inexpertis."

(Sweet is war to those who have never experinced it.) Roman Proverb

Gold leader

01-31-2001, 10:55 AM

Originally posted by Admiral:

a function is anything that passes the the y axis only once.

Admiral, you should have known better. f(x) = 1/x is a function, but it never actually passes the y-axis.

a function is anything that passes the the y axis only once.

Admiral, you should have known better. f(x) = 1/x is a function, but it never actually passes the y-axis.

Rogue Nine

01-31-2001, 11:15 AM

Not true. Try the function (x-4)^2/x-2.

Gold leader

01-31-2001, 11:35 AM

Try what. Differentiate?

Rogue Nine

01-31-2001, 03:10 PM

Graph it.

Keyan Farlander

01-31-2001, 05:29 PM

Why? It's pretty obvious what it will look like.

Rogue Nine

01-31-2001, 05:45 PM

Yeah, but no one else is a frickin' genius like you, Keyan.

Keyan Farlander

01-31-2001, 06:07 PM

Um, thanks http://www.xwingalliance.com/forums/smile.gif But I meant what is your point about graphing that? I'm not sure what you're getting at. Something about the discontinuity?

Rogue Nine

01-31-2001, 06:40 PM

Tis a line, isn't it?

------------------

Love people. Use things. Not vice versa.

XWA's Resident Finance Manager

------------------

Love people. Use things. Not vice versa.

XWA's Resident Finance Manager

Admiral

01-31-2001, 07:06 PM

I am bad with graphs, I like using my calculator for those.

------------------

"Dulce bellum inexpertis."

(Sweet is war to those who have never experinced it.) Roman Proverb

------------------

"Dulce bellum inexpertis."

(Sweet is war to those who have never experinced it.) Roman Proverb

Rogue Nine

01-31-2001, 07:21 PM

So try it! Plug it in!

Keyan Farlander

01-31-2001, 09:17 PM

A line? That function is not a line. Speak up, R9, what are you getting at?

Cmdr. Cracken

01-31-2001, 10:47 PM

so, how would i evaluate this.....?

g(x)=x^2-3x

when g(4)

would I just substitue x for for, since g(4)?

g(x)=x^2-3x

when g(4)

would I just substitue x for for, since g(4)?

Cmdr. Cracken

01-31-2001, 10:50 PM

I think i know what R9 is getting at. a function is any line on a graph that passes the vert. Line test.

Vertical line test=You place a vertical line anywhere on the line. if the vertical line crosses the line more than ONCE, then the line is not a function.

R9's sentence (x-4)^2/x-2 will probably fail this test.

Vertical line test=You place a vertical line anywhere on the line. if the vertical line crosses the line more than ONCE, then the line is not a function.

R9's sentence (x-4)^2/x-2 will probably fail this test.

Keyan Farlander

01-31-2001, 11:07 PM

Yes, that is how you do it. And that thing passes the vertical line test with flying colors.

JR2000Z

01-31-2001, 11:09 PM

Hehehehehe...*cough* sorry. http://www.xwingalliance.com/forums/biggrin.gif

Gold leader

02-01-2001, 08:36 AM

Originally posted by Cmdr. Cracken:

so, how would i evaluate this.....?

g(x)=x^2-3x

g(4)=4^2-3*4=4

piece o' cake.

so, how would i evaluate this.....?

g(x)=x^2-3x

g(4)=4^2-3*4=4

piece o' cake.

Zoom Rabbit

02-01-2001, 09:27 AM

I was told we didn't have to do math...!

Rogue Nine

02-01-2001, 10:22 AM

I'm too sleepy. Math stinks. 'Specially at 6:30 in the morn.

Zoom Rabbit

02-01-2001, 10:40 AM

Cool.

*(Plays videogames instead.)*

*(Plays videogames instead.)*

Rogue Nine

02-01-2001, 10:41 AM

You're a woozer...don't you have to go to school?

Jem

02-05-2001, 07:28 PM

Here is a twisting math resolution for you guys:

1+1=1 so 1+1=3 (we can also say that 1=2=3)

and this is why (the bold parts are the changes that occured):

(a+b)(a-b) = aČ - ab + ba - bČ

(a+b)(a-b) = aČ - bČ

_Now divide each side by (a-b), we have:

[(a+b)(a-b)]/(a-b) = (aČ - bČ)/ (a-b)

_We now have:

(a+b) = (aČ - bČ) / (a-b)

_Let us suggest that: a = b = 1

which gives us:

1+1 = (1-1) / (1-1)

_There is the same terme above and under the division so it is equal 1

so we have:

1+1 = 1

_add one at each side:

1+1+1 = 1+1

3 = 1 + 1

There you go!

(we can also conclude that 2 + 2 = 5 and etc. Also we can show that 1=2=3=4=5=etc)

Any comments?

1+1=1 so 1+1=3 (we can also say that 1=2=3)

and this is why (the bold parts are the changes that occured):

(a+b)(a-b) = aČ - ab + ba - bČ

(a+b)(a-b) = aČ - bČ

_Now divide each side by (a-b), we have:

[(a+b)(a-b)]/(a-b) = (aČ - bČ)/ (a-b)

_We now have:

(a+b) = (aČ - bČ) / (a-b)

_Let us suggest that: a = b = 1

which gives us:

1+1 = (1-1) / (1-1)

_There is the same terme above and under the division so it is equal 1

so we have:

1+1 = 1

_add one at each side:

1+1+1 = 1+1

3 = 1 + 1

There you go!

(we can also conclude that 2 + 2 = 5 and etc. Also we can show that 1=2=3=4=5=etc)

Any comments?

Keyan Farlander

02-05-2001, 11:08 PM

Um, you can "prove" almost anything if you sneak a divide by zero in there. There are so many bogus proofs that use this that it can be called "a really old joke" in math circles. I actually seem to recall us having this discussion here a little while ago (although it might be somewhere else I was thinking about). I remember the first time I saw something like this. It WAS actually pretty freaky http://www.xwingalliance.com/forums/smile.gif

Nitro

02-06-2001, 01:31 AM

If it passed the vertical line more then once, that would make it a parabola, and therefore quadratic, and not a linear equation.

I hate quadratic equations... not cause they don't make sense, or they're hard... They're just the same thing over and over again... No challenge.

I hate quadratic equations... not cause they don't make sense, or they're hard... They're just the same thing over and over again... No challenge.

Nitro

02-06-2001, 01:36 AM

I'm doing Enriched Grade 11 Math, and Advanced Enriched Grade 12 Math in the same semester so I can do my Calculus and AP Math next year... but we haven't started any serious algebra yet, so I'm lost, but wanted to feel cool and in with the math geeks, so I posted some random fact that's true... Shows how great my life is... I'm reaching to the Math geeks for acceptance. http://www.xwingalliance.com/forums/biggrin.gif

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Hello, my name is Nitro, and I'm calling from BBM Bureau of Measurement, the radio ratings company...

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Hello, my name is Nitro, and I'm calling from BBM Bureau of Measurement, the radio ratings company...

Keyan Farlander

02-06-2001, 02:18 AM

Actually, there was a lot wrong with what you said http://www.xwingalliance.com/forums/smile.gif I think you meant horizontal line, first of all. Even so, it might be cubic or quartic or anything else of higher order. Not to worry, though - I accept you on behalf of all us math geeks http://www.xwingalliance.com/forums/biggrin.gif

Zoom Rabbit

02-06-2001, 12:09 PM

I represent the silent multitude of people who have no clear idea what you 'math geeks' have been talking about. http://www.xwingalliance.com/forums/wink.gif

I thought a 'vertical line test' was that embarrassing thing the cops make you do on the side of the road with everyone staring at you as they drive past...

I thought a 'vertical line test' was that embarrassing thing the cops make you do on the side of the road with everyone staring at you as they drive past...

Nitro

02-06-2001, 06:10 PM

Yeah... I knew that... http://www.xwingalliance.com/forums/biggrin.gif

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Hello, my name is Nitro, and I'm calling from BBM Bureau of Measurement, the radio ratings company...

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Hello, my name is Nitro, and I'm calling from BBM Bureau of Measurement, the radio ratings company...

Jem

02-06-2001, 07:29 PM

Originally posted by Keyan Farlander:

Um, you can "prove" almost anything if you sneak a divide by zero in there.

Yeah, I was waiting till someone mentioned it befor discussing it:

what if you do not suppose a zero but the term (1-1), therefor the rule can be applied, can it?

[This message has been edited by Jem (edited February 06, 2001).]

Um, you can "prove" almost anything if you sneak a divide by zero in there.

Yeah, I was waiting till someone mentioned it befor discussing it:

what if you do not suppose a zero but the term (1-1), therefor the rule can be applied, can it?

[This message has been edited by Jem (edited February 06, 2001).]

Cmdr. Cracken

02-06-2001, 10:53 PM

Jem, the term (1-1)=0

so basically, in your proof, your using an euphemism for 0.

so basically, in your proof, your using an euphemism for 0.

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