Winamp & Shoutcast Forums Maths

 15th June 2005, 10:49 #1 mysterious_w Forum King     Join Date: Dec 2003 Location: Good ol' Britain Posts: 2,750 Maths Had my GCSE maths paper today. Went pretty well I thought, but they was a couple of simple algebra questions that stumped me, so I wrote them on my hand in the hope that one of you would know how to do it: ```code:1. Factorise: a^2-9b^2 2. Simplify Fully: x^2-3x ------- x^2-8x+15 ```
 15th June 2005, 11:03 #2 shakey_snake Forum Domo     Join Date: Jan 2004 Location: Everyone, get over here for the picture! Posts: 4,313 (a+3b)(a-3b) (factorise should be spelt with a 'z' ) 2. x(x-3) ------ (x-3)(x-5) x ----- x-5 where is Mathml hen we need it... elevatorladyelevatorladyelevatorladyelevatorladyelevatorladylevitateme
 15th June 2005, 11:49 #3 Wolfgang Forum King   Join Date: Mar 2004 Posts: 3,069 Actually, it's only with a z where you live. Sometimes you Americans seem to forget there are other countries.
 15th June 2005, 11:55 #4 ElChevelle Moderator Alumni     Join Date: Jun 2000 Location: the MANCANNON! Posts: 22,436 There are?
 15th June 2005, 14:14 #5 matt_69 Sunshine(Major Dude)     Join Date: Jan 2003 Location: Brisvegas, Australia Posts: 1,248 what grade of maths is that? i was strugling to remember the rules for that, and i do 2 maths at school . tho i do challenge you to find the derivative of 3x^4+3x using first principals haha (not really that difficult but hey, i did that on my exam today)
15th June 2005, 14:23   #6
Wolfgang
Forum King

Join Date: Mar 2004
Posts: 3,069
Quote:
 Originally posted by ElChevelle There are?
Yeah. Canada is actually a separate country, you know.

15th June 2005, 14:58   #7
k_rock923
\m/
(Forum King)

Join Date: Jul 2003
Location: /bin/bash
Posts: 7,850
Quote:
 Originally posted by matt_69 what grade of maths is that? i was strugling to remember the rules for that, and i do 2 maths at school . tho i do challenge you to find the derivative of 3x^4+3x using first principals haha (not really that difficult but hey, i did that on my exam today)
wtf is first principals? Is that the same thing as the power rule? Anyway, 12x^3 + 3

Never underestimate the bandwidth of a station wagon full of tapes hurtling down the highway.

 15th June 2005, 15:07 #8 Schmeet Major Dude     Join Date: Oct 2004 Location: The timid west Posts: 1,444 Heh, i did this paper too. Hadn't a clue about these ones but the rest of the paper was pretty okish.
15th June 2005, 15:58   #9
xzxzzx
Forum King

Join Date: Aug 2002
Posts: 7,254
Quote:
 Originally posted by Wolfgang Yeah. Canada is actually a separate country, you know.
Yeah, mostly. Same country code in the phone system. Same language (basically). Same accent as the people living on the border to Canada.

Anyway Wolfgang, shakey_snake didn't say that it is spelt with a "z", only that it should be. =P

Freedom of speech is the basic freedom of humanity. When you've lost that, you've lost everything.
1\/\/4y 34|<\$p4y 1gp4y 33714y, 0d4y 0uy4y? | Roses are #FF0000; Violets are #0000FF; chown -R \${YOU} ~/base
The DMCA. It really is that bad. : Count for your life.

15th June 2005, 16:55   #10
hgnis
Hobbit Humper
Forum King

Join Date: Sep 2002
Location: banned camp
Posts: 4,121
Quote:
 Originally posted by matt_69 tho i do challenge you to find the derivative of 3x^4+3x using first principals haha (not really that difficult but hey, i did that on my exam today)
3x(x+1)(x^2-x+1)

=> 3x(x+1)[(x-1/2)^2+3/4]

QED.

I am so important I feel the need to let it be known like a liberal discovering the internets for the first time. Uh hur hur hur. I also wash myself with a rag on a stick.
Realitybites
<3

 15th June 2005, 18:16 #11 mike-db Pancakes!(Major Dude)     Join Date: Feb 2005 Location: Colour, if you're, you know... Posts: 3,523 2+2=4 SEX APPEAL UP IN HERE! (╯°□°）╯︵ ┻━┻
15th June 2005, 20:30   #12
shakey_snake
Forum Domo

Join Date: Jan 2004
Location: Everyone, get over here for the picture!
Posts: 4,313
Quote:
 Originally posted by Wolfgang Actually, it's only with a z where you live. Sometimes you Americans seem to forget there are other countries.
I was joking (hence the winking), but thanks for trying to be informative...

15th June 2005, 23:32   #13
Wolfgang
Forum King

Join Date: Mar 2004
Posts: 3,069
Quote:
 Originally posted by xzxzzx Anyway Wolfgang, shakey_snake didn't say that it is spelt with a "z", only that it should be. =P
SHOULD BE? I may be a bit pissdd, but I feel I have to be as obnoxious (or informative??) as possible here. You lot have desecrated the English language. Particulalry with things like "thru", "aluminum" and the removal of the letter U from words like colour and neighbour. I also find the labelling of perfectl y arable earth as "dirt". Dirt is simply stuff you throw in the bin, not the stuff you farm with.

16th June 2005, 01:15   #15
matt_69
Sunshine
(Major Dude)

Join Date: Jan 2003
Location: Brisvegas, Australia
Posts: 1,248
Quote:
 Originally posted by hgnis 3x(x+1)(x^2-x+1) => 3x(x+1)[(x-1/2)^2+3/4] QED.
nah, k_rock923 got the answer, its 12x^3 + 3. and yeah, first principals is the very long and stupid way of doing the rule. uses limits and shit, too much work if you ask me.

 16th June 2005, 02:17 #16 Spazz333 Major Dude     Join Date: Nov 2003 Location: Limbo Posts: 1,498 Dirt is dirt is dirt to city folk. Go in the rural areas where we have soil. :P
16th June 2005, 12:13   #17
Wolfgang
Forum King

Join Date: Mar 2004
Posts: 3,069
Quote:
 Originally posted by shakey_snake Wolfgang... You are American.
This is true, but does not mean I speak American English. Anyway, it would be a bit pedantic to start referring to you as a United Statesean or USAean.

16th June 2005, 15:38   #18
xzxzzx
Forum King

Join Date: Aug 2002
Posts: 7,254
Quote:
 Originally posted by Wolfgang "thru"
"Thru"?

I'd smack someone for writing "thru".

Your examples are pitiful, wolfgang. The vast majority of differences between (American) English and British (=P) are arbitrary, such as the spelling of "check" (cheque), or the different meanings of things like "chips".

Both of them have about the same degree of self-consistancy. So here's the thing: economic powers make the languages. It's always been that way. Therefore, British English is actually non-standard, because American English is spoken by the world's largest economic power. Which is fine, I'm not trying to say that you should speak American English. You can speak whatever you like. But don't try to pass off this "my language is better than yours" crap.

And Wolfgang is not "American", shakey_snake. "American" is someone from the United States (this is even more prevalent in British English, truth be told). You might call Wolfgang "panamarican".

Freedom of speech is the basic freedom of humanity. When you've lost that, you've lost everything.
1\/\/4y 34|<\$p4y 1gp4y 33714y, 0d4y 0uy4y? | Roses are #FF0000; Violets are #0000FF; chown -R \${YOU} ~/base
The DMCA. It really is that bad. : Count for your life.

16th June 2005, 16:01   #19
shakey_snake
Forum Domo

Join Date: Jan 2004
Location: Everyone, get over here for the picture!
Posts: 4,313
Quote:
 Originally posted by xzxzzx And Wolfgang is not "American", shakey_snake. "American" is someone from the United States (this is even more prevalent in British English, truth be told). You might call Wolfgang "panamarican"[sic].
Yes, we from the US typically think that we are the only ones considered American, but most of Central and South America would repectfully disagree with you. Just an example of things you pick up when you travel.

here is decent documentation on differences between the two Englishes.

Wolfgang, you haven't started using 'vosotros' have you?

16th June 2005, 17:53   #20
beanboy89
(Major Dude)
isn't very custom

Join Date: Nov 2003
Location: Pennsylvania, USA
Posts: 2,004
Quote:
 Originally posted by shakey_snake here is decent documentation on differences between the two Englishes.

16th June 2005, 17:55   #21
crackity
Senior Member

Join Date: Jul 2004
Location: The East Side
Posts: 120
Quote:
 Originally posted by matt_69 what grade of maths is that? i was strugling to remember the rules for that, and i do 2 maths at school . tho i do challenge you to find the derivative of 3x^4+3x using first principals haha (not really that difficult but hey, i did that on my exam today)
wow had to see if I actually remmeber this stuff:

```code:
df/dx = lim h->0 (f(x+h) - f(x)) / h
= lim h->0 (3(x+h)^4 + 3(x+h) - 3x^4 - 3x) / h
= lim h->0 (3x^4 + 12(x^3)h + 18(x^2)(h^2) + 12xh^3 + 3h^4 + 3x + 3h - 3x^4 - 3x) / h
= lim h->0 (12(x^3)h + 18(x^2)(h^2) + 12xh^3 + 3h^4 + 3h) / h
= lim h->0 12x^3 + 18hx^2 + 12xh^3 + 3h^4 + 3
= 12x^3 + 3
```

Crackity
QuickTracks: Info & Most Recent

 16th June 2005, 20:16 #22 hgnis Hobbit Humper Forum King     Join Date: Sep 2002 Location: banned camp Posts: 4,121 oops, Matt I was thinking about the divisor-quotient factors not derivatives at the time. I am so important I feel the need to let it be known like a liberal discovering the internets for the first time. Uh hur hur hur. I also wash myself with a rag on a stick. Realitybites <3
17th June 2005, 13:50   #23
Wolfgang
Forum King

Join Date: Mar 2004
Posts: 3,069
Quote:
 Originally posted by xzxzzx "Thru"? I'd smack someone for writing "thru". Your examples are pitiful, wolfgang. The vast majority of differences between (American) English and British (=P) are arbitrary, such as the spelling of "check" (cheque), or the different meanings of things like "chips". But don't try to pass off this "my language is better than yours" crap. And Wolfgang is not "American", shakey_snake. "American" is someone from the United States (this is even more prevalent in British English, truth be told). You might call Wolfgang "panamarican".
Pitiful or not, I don't like them. Hearing or reading "aluminum" makes me cringe. It occurs to a lesser extent with "harbor" and "favorite", but I still don't like them. That's all. And if you read what I wrote, there was some sarcasm and light humour in it, so don't pounce on me and get all defensive about it. I never said my language is better, though it's quite obvious I do think it is better. We are all entitled to our own opinions, just like you probably believe your country is amazing and better than any other.*

I think you'll find most people who aren't American believe British English is "proper English". It's the original item. And I'm fine with the US being the biggest economy, despite how it abuses this position, and I do agree with you in that it's only natural for the language spoken in this country to proliferate around the world. I just don't like the language.

I am American. I live in America, hence I am American. It annoys me how Brits and other people refer to the USA as "America", as if it were the only important thing in America (the continent). I think it's very arrogant of you to say that only people from your country are Americans. I just have to adapt to everyone else and refer to you as an American, but I refuse to refer to your country as America.

* NOTE: I'm speculating. Don't chew my head off. It's sad I actually have to point this out.

Quote:
 Wolfgang, you haven't started using 'vosotros' have you?
hah. no! never! I'm not a great fan of Spanish Spanish. Incidentally, the worst-sounding by far, in my opinion, are Venezuelan and Chilean Spanish.

Old Spanish, like what is spoken in Spain and to some extent Argentina, just sounds like using "ye", "thou", "thine" and such words to a South American. I don't dislike it, I just think it sounds odd.

17th June 2005, 14:42   #24
matt_69
Sunshine
(Major Dude)

Join Date: Jan 2003
Location: Brisvegas, Australia
Posts: 1,248
Quote:
 Originally posted by crackity wow had to see if I actually remmeber this stuff: ```code: df/dx = lim h->0 (f(x+h) - f(x)) / h = lim h->0 (3(x+h)^4 + 3(x+h) - 3x^4 - 3x) / h = lim h->0 (3x^4 + 12(x^3)h + 18(x^2)(h^2) + 12xh^3 + 3h^4 + 3x + 3h - 3x^4 - 3x) / h = lim h->0 (12(x^3)h + 18(x^2)(h^2) + 12xh^3 + 3h^4 + 3h) / h = lim h->0 12x^3 + 18hx^2 + 12xh^3 + 3h^4 + 3 = 12x^3 + 3 ```
spot on, tho i do mine a bit differently. i work out the f(x+h) bit on the side, then just sub it in. makes it look a lot neater .

you wouldn't happen to b australian would you?

 17th June 2005, 15:35 #25 k_rock923 \m/(Forum King)     Join Date: Jul 2003 Location: /bin/bash Posts: 7,850 Why use the method with limits? It only creates more work. Never underestimate the bandwidth of a station wagon full of tapes hurtling down the highway.
17th June 2005, 19:29   #26
zootm
Forum King

Join Date: Jan 2002
Location: the nether reaches of bonnie scotland
Posts: 13,375
Quote:
 Originally posted by shakey_snake Yes, we from the US typically think that we are the only ones considered American, but most of Central and South America would repectfully disagree with you. Just an example of things you pick up when you travel.
Apparently (I read a linguistics article on this for some reason, was linked to it), nowadays, "American" does mean "from the US". people from North America, though, are "North American", and likewise "South American". But the generic term refers solely to people from the states.

Just common usage, I suppose!

Quote:
 Originally posted by shakey_snake where is Mathml hen we need it...
I'll mark it up in LaTeX and post it as an image, if you really want.

17th June 2005, 21:01   #27
crackity
Senior Member

Join Date: Jul 2004
Location: The East Side
Posts: 120
Quote:
 Originally posted by k_rock923 Why use the method with limits? It only creates more work.
The limits way is the definition of a derivative, and the shortcuts that your are talking about are all derived from the limits way. So by learning the limits way you have the general solution and can solve problems that dont take a cookie cutter type form.

But yes, for cookie cutter type problems, using the known formulas is much faster.... as long as your remember the formulas.

Quote:
 Originally posted by matt_69 spot on, tho i do mine a bit differently. i work out the f(x+h) bit on the side, then just sub it in. makes it look a lot neater . you wouldn't happen to b australian would you?
nope, just a silly american who got drunk one day and decided to get a math major with my comp sci degree.

Crackity
QuickTracks: Info & Most Recent

17th June 2005, 21:32   #28
xzxzzx
Forum King

Join Date: Aug 2002
Posts: 7,254
Quote:
 Originally posted by zootm Apparently (I read a linguistics article on this for some reason, was linked to it), nowadays, "American" does mean "from the US". people from North America, though, are "North American", and likewise "South American". But the generic term refers solely to people from the states. Just common usage, I suppose!
<3

Freedom of speech is the basic freedom of humanity. When you've lost that, you've lost everything.
1\/\/4y 34|<\$p4y 1gp4y 33714y, 0d4y 0uy4y? | Roses are #FF0000; Violets are #0000FF; chown -R \${YOU} ~/base
The DMCA. It really is that bad. : Count for your life.

 Winamp & Shoutcast Forums Maths