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#1 2016-04-26 04:35:42

Thuhina
Member
Registered: 2016-04-26
Posts: 7

Trigonometry-CD equations

"Cos(A-B) - Cos(A-B) = 2SinASinB"

I saw this equation on this site. But it is quite different from what i learned in the class. What i lerned was this. "Cos(A-B) - Cos(A+B) = 2SinASinB" which one is correct?

Last edited by Thuhina (2016-04-26 04:39:46)

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#2 2016-04-26 05:58:25

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

Re: Trigonometry-CD equations

Hi;

"Cos(A-B) - Cos(A-B) = 2SinASinB  is not an identity. It looks like a typo.


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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#3 2016-04-26 06:02:56

Thuhina
Member
Registered: 2016-04-26
Posts: 7

Re: Trigonometry-CD equations

Oh thanx a lot! I hope It's better if u correct that. It's misleading.

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#4 2016-04-26 06:04:02

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

Re: Trigonometry-CD equations

Where did you see it?


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 2016-04-26 06:09:50

Thuhina
Member
Registered: 2016-04-26
Posts: 7

Re: Trigonometry-CD equations

http://www.mathisfunforum.com/viewtopic.php?id=3290 it's in this page.

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#6 2016-04-26 06:14:01

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

Re: Trigonometry-CD equations

I have deleted it, thanks for spotting that.


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 2016-04-26 06:17:05

Thuhina
Member
Registered: 2016-04-26
Posts: 7

Re: Trigonometry-CD equations

It's still there.

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#8 2016-04-26 06:18:58

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

Re: Trigonometry-CD equations

It will take some time to edit. The server is responding very, very slowly right now.


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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