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## #1 2014-07-02 12:31:00

Agnishom
Real Member
From: Riemann Sphere
Registered: 2011-01-29
Posts: 23,198
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### Even more trig

If sin(B+C-A),sin(C+A-B) and sin(A+B-C)are in A.P.; then cot A,cot B,cot C are in -
(a)  GP
(b)  HP
(c)  AP
(d)  None of these.

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## #2 2014-07-14 04:19:24

Nehushtan
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## #3 2014-07-14 04:49:48

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,000

### Re: Even more trig

M says b. I haven't gotten to the solution analytically yet, though.

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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## #4 2014-07-14 04:59:17

bobbym
From: Bumpkinland
Registered: 2009-04-12
Posts: 102,304

### Re: Even more trig

Hi;

May I see what you did with M to get that?

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
A number by itself is useful, but it is far more useful to know how accurate or certain that number is.

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## #5 2014-07-14 05:01:47

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,000

### Re: Even more trig

Sure!

``````FullSimplify[Sin[b + c - a] + Sin[a + b - c] == 2 Sin[a + c - b]]

2 Cos[a] Cos[c] Sin[b] == Cos[b] Sin[a + c]``````

Last edited by anonimnystefy (2014-07-14 05:02:14)

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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## #6 2014-07-14 05:12:48

bobbym
From: Bumpkinland
Registered: 2009-04-12
Posts: 102,304

### Re: Even more trig

I do not understand it.

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
A number by itself is useful, but it is far more useful to know how accurate or certain that number is.

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## #7 2014-07-14 05:18:44

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,000

### Re: Even more trig

What do you not understand? I just rearranged the result a bit and got the answer.

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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## #8 2014-07-14 05:20:56

bobbym
From: Bumpkinland
Registered: 2009-04-12
Posts: 102,304

### Re: Even more trig

They are in AP?

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
A number by itself is useful, but it is far more useful to know how accurate or certain that number is.

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## #9 2014-07-14 05:22:00

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,000

### Re: Even more trig

The cot's are in HP.

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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## #10 2014-07-14 05:26:16

bobbym
From: Bumpkinland
Registered: 2009-04-12
Posts: 102,304

### Re: Even more trig

How are you representing the sines in AP is what I meant?

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
A number by itself is useful, but it is far more useful to know how accurate or certain that number is.

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## #11 2014-07-14 05:31:10

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,000

### Re: Even more trig

The same as Nehushtan did.

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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## #12 2014-07-14 05:32:36

bobbym
From: Bumpkinland
Registered: 2009-04-12
Posts: 102,304

### Re: Even more trig

Okay, I see what you saying.

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
A number by itself is useful, but it is far more useful to know how accurate or certain that number is.

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## #13 2014-07-14 05:39:03

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,000

### Re: Even more trig

Now to do it by hand...

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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## #14 2014-07-14 05:46:37

bobbym
From: Bumpkinland
Registered: 2009-04-12
Posts: 102,304

### Re: Even more trig

You have the result, now you just have to back engineer the how.

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
A number by itself is useful, but it is far more useful to know how accurate or certain that number is.

Offline

## #15 2014-07-14 05:52:56

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,000

### Re: Even more trig

I think I figured it out. I will post it when I write it out.

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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## #16 2014-07-14 06:07:10

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,000

### Re: Even more trig

Here's the solution.

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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## #17 2014-07-14 06:16:13

bobbym
From: Bumpkinland
Registered: 2009-04-12
Posts: 102,304

### Re: Even more trig

Hi;

Got to get off, will look at it when I get back. You did good.

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
A number by itself is useful, but it is far more useful to know how accurate or certain that number is.

Offline

## #18 2014-07-14 06:21:17

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

### Re: Even more trig

Expanding gives:

hence in H.P.

"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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## #19 2014-07-14 06:27:55

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,000

### Re: Even more trig

Hi bobbym

See you later!

Thanks.

Last edited by anonimnystefy (2014-07-14 06:29:01)

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.

Offline