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## #1 2009-08-22 09:54:43

Guest

### Precalculus

Hi all,

I am working on some math problems, and there are two that I just can not get.

The first one is use the given information given to find the exact value of the trigonometric function.

cos Q=1/4, csc Q>0  Find sin Q/2

The second problem I have is solve the equation on the interval [0,2pi]

cos2x=sqrt3/2

If anyone can help me it would be greatly appreciated.

Thank you.

## #2 2009-08-22 10:33:06

juriguen
Member
Registered: 2009-07-05
Posts: 59

### Re: Precalculus

Hi

The first one I would say:

So every requirement holds.

The second:

Hope it helps!

Jose

Make everything as simple as possible, but not simpler. -- Albert Einstein

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## #3 2009-08-22 11:18:26

Guest

### Re: Precalculus

Thanks so much.  I have three other problems that I still can not get.  Same like before solve the equation on the interval [0,2pi]

2sin^2x=sinx

(tanx+1)(cosx+1)=0

2cos^2x+sinx-2=0

## #4 2009-08-22 12:13:43

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

### Re: Precalculus

the roots are:

Last edited by bobbym (2009-08-22 12:52:16)

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 2009-08-22 19:32:59

juriguen
Member
Registered: 2009-07-05
Posts: 59

### Re: Precalculus

You're welcome

Jose

Make everything as simple as possible, but not simpler. -- Albert Einstein

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## #6 2009-08-22 20:08:03

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

### Re: Precalculus

(tanx+1)(cosx+1)=0

These are the roots:

Last edited by bobbym (2009-08-22 20:10:48)

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.

Offline

Guest

## #8 2009-08-23 05:41:15

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