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## #1 2011-06-21 06:42:22

soroban
Member
Registered: 2007-03-09
Posts: 452

### Rubbish?

tan(A+B) =  sin^2A - sin^2B/sinA cosA - sinB cosB

. .

. .

. .

.

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## #2 2011-06-21 07:38:26

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,037

### Re: Rubbish?

hi soroban
you tell him.
the person who posted "what rubbish is this??" 'clearly' doesn't know the rules for trigonometric functions of sums.

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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## #3 2011-06-21 10:10:06

MathsIsFun
Registered: 2005-01-21
Posts: 7,651

### Re: Rubbish?

They seem to think we can read their mind.

"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman

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## #4 2011-06-21 10:53:14

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

### Re: Rubbish?

Hi;

Soon to be released in JAMA.

Definition: Bracketophobia - an unusual or unwarranted fear of brackets or parentheses.

Treatment: Latexicillin or OxyLatex. Massive doses required.

Contraindications: Some patients have been known to become aggressive when the slightest suggestion of bracketing is made. Stronger treatment may be required.

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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## #5 2011-06-24 05:40:14

soroban
Member
Registered: 2007-03-09
Posts: 452

. .

.

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## #6 2011-06-24 05:45:06

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

### Re: Rubbish?

Hi soroban;

Have you seen the movie "A Beautiful Mind?" He would fill up a blackboard, writing at all angles so that all the space would be used. He would even write inside of a zero.

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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## #7 2011-06-24 06:09:51

gAr
Member
Registered: 2011-01-09
Posts: 3,479

### Re: Rubbish?

I hate watching movies involving science/mathematics/computers.
Rarely are they anywhere near reality.

Someone looks at a code, his mind magically deciphers it!
Someone presses keyboard keys randomly, and he breaks into a system!

Even the media are no better.
Better stay uninformed than disinformed!!

"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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## #8 2011-06-24 06:18:56

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

### Re: Rubbish?

True! The Numbers show on tv is among the worst.

In the movies computers are so smart. They always take over the world.

But I am getting carried away, sticking to the topic.

I can decipher it but not condone it. When I was young I used to write math pretty much like that. Used to make my teachers very angry.

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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## #9 2011-06-24 06:26:52

gAr
Member
Registered: 2011-01-09
Posts: 3,479

### Re: Rubbish?

I think it's not out of topic, it's "rubbish"!

Anyway,regarding that serial assignment, it would be fun if it's shown to a programmer!

"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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## #10 2011-06-27 12:41:06

soroban
Member
Registered: 2007-03-09
Posts: 452

### Re: Rubbish?

gAr wrote:

I hate watching movies involving science/mathematics/computers.
Rarely are they anywhere near reality.

I agree . . .

Two men are playing a chess game.
The villain makes a move and sits back, smiling smugly.
The hero (usually James Bond) looks a bit concerned,
. . then makes a move . . . Checkmate!
The villain's jaw drops . . . totally stunned!

You'll never convince me that someone who plays chess
. . would overlook a mate-in-one ... and walk into it.

.

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## #11 2011-06-27 14:59:05

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

### Re: Rubbish?

Hi;

Although those type of errors are much more prevalent in weaker players they occasionally pop up even in grandmaster games.

I believe both Tigran Petrosian and Emanuel Lasker, both world champions walked into simple mates in the middle of the board. Petrosian lost his queen in a very important tournament to determine the next challenger. Bobby Fischer was guilty of a touch move as was Garry Kasparov ( also world champions ).

My worst one was walking into a simple 2 move mate on the back rank.

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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