Arctangent confusing to me

Trigonometric ratios and functions, the unit circle, inverse trig functions, identities, trig graphs, etc.
AmySaunders
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Arctangent confusing to me

Postby AmySaunders » Fri Jul 09, 2010 7:44 pm

This is my problem and I can not figure it out!!!:
Arctan[tan(7pi/6)]
I have tried to use the reference triangles but no matter what I do, I always come out with the answer: 7pi/6. The answer book, however, says that the answer is pi/6. Any and all help will be appreciated!!

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Martingale
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Re: Arctangent confusing to me

Postby Martingale » Fri Jul 09, 2010 9:10 pm

AmySaunders wrote:This is my problem and I can not figure it out!!!:
Arctan[tan(7pi/6)]
I have tried to use the reference triangles but no matter what I do, I always come out with the answer: 7pi/6. The answer book, however, says that the answer is pi/6. Any and all help will be appreciated!!


can't be an answer since is always between

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Martingale
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Re: Arctangent confusing to me

Postby Martingale » Fri Jul 09, 2010 9:36 pm

AmySaunders wrote:Any and all help will be appreciated!!


remember that tan is pi periodic.

so

AmySaunders
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Re: Arctangent confusing to me

Postby AmySaunders » Mon Jul 12, 2010 10:15 pm

I'm sorry. I still don't understand? Is there a lesson on here you could refer me to? What does pi periodic mean?

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Martingale
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Re: Arctangent confusing to me

Postby Martingale » Mon Jul 12, 2010 11:22 pm

AmySaunders wrote:What does pi periodic mean?


http://www.wolframalpha.com/input/?i=graph+tan%28x%29

notice how the graph repeats..it does this very pi units


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