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**lindah****Member**- Registered: 2010-01-25
- Posts: 121

Hi guys,

I just wanted to ask if you guys are aware of any shortcuts/rules when expanding something along the lines of:

I can manually do this, however it is a past exam question, thus wanted to find out a quicker way to do this. I realise the last two terms cancel, but it's just a little for when I'm assessing if Brownian motion is a martingale.

I've come across only cubic expansions of the form (a+b)^3 so far in my searches,

Thank you in advance for any feedback

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**gAr****Member**- Registered: 2011-01-09
- Posts: 3,481

Hi lindah,

There's a small wikipedia entry on trinomial expansion, which looks easy to remember.

The cubic expansion looks similar to that of binomial's

"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense" - Buddha?

"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."

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**lindah****Member**- Registered: 2010-01-25
- Posts: 121

Hi gAr,

Thank you for that!

That was exactly what I was looking for, the word trinomial seemed to elude me on my searches.

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**gAr****Member**- Registered: 2011-01-09
- Posts: 3,481

Hi lindah,

You're welcome!

"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense" - Buddha?

"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."

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**anonimnystefy****Real Member**- From: Harlan's World
- Registered: 2011-05-23
- Posts: 16,039

Hi gAr

I am sorry for being boring and tedious with this, but have you gotten around to checking the solutions in your Series thread?

*Last edited by anonimnystefy (2012-06-24 15:11:28)*

Here lies the reader who will never open this book. He is forever dead.

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

The knowledge of some things as a function of age is a delta function.

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**gAr****Member**- Registered: 2011-01-09
- Posts: 3,481

Hi anonimnystefy,

I'll check today, I forgot about it.

"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense" - Buddha?

"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."

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**anonimnystefy****Real Member**- From: Harlan's World
- Registered: 2011-05-23
- Posts: 16,039

Okay. Thank you.

Btw, how old are you?

Here lies the reader who will never open this book. He is forever dead.

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

The knowledge of some things as a function of age is a delta function.

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**gAr****Member**- Registered: 2011-01-09
- Posts: 3,481

You're welcome, younger than bobbym!

"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."

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**anonimnystefy****Real Member**- From: Harlan's World
- Registered: 2011-05-23
- Posts: 16,039

So, you are being secretive too? Okay then

Here lies the reader who will never open this book. He is forever dead.

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

The knowledge of some things as a function of age is a delta function.

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**gAr****Member**- Registered: 2011-01-09
- Posts: 3,481

Mathematics is more interesting to think about.

"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."

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**anonimnystefy****Real Member**- From: Harlan's World
- Registered: 2011-05-23
- Posts: 16,039

Whatg does that have to do with you not revealing your age?

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

The knowledge of some things as a function of age is a delta function.

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**lindah****Member**- Registered: 2010-01-25
- Posts: 121

They are both child prodigies under 20

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**anonimnystefy****Real Member**- From: Harlan's World
- Registered: 2011-05-23
- Posts: 16,039

Who is?

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

The knowledge of some things as a function of age is a delta function.

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**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606

Me and gAr of course!

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

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