Nicholas D. answered • 06/03/21
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University of Michigan PhD Graduate and Experienced STEM Tutor
If you have your trig identities available, review angle sum and difference identities.
Nicholas D.
No problem, there is a great website by the name of Purple Math, which has a lot of great resources. Here is the link: https://www.purplemath.com/modules/idents.htm
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06/03/21
Mia J.
can you please help me
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06/03/21
Nicholas D.
I am not sure if wyzant is letting you view that link, so here the identity you would need for this problem: cos(α – β) = cos(α) cos(β) + sin(α) sin(β). Do you know what the alpha and beta values would be for your question?
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06/03/21
Mia J.
no i still dont undertsand
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06/03/21
Nicholas D.
Instead of cos(alpha - beta), your question is cos(x - 2*pi/3). So your alpha is x and your beta is 2*pi/3. If you plug those values into the identity, you can express the result in sines and cosines.
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06/03/21
Mia J.
so what would it be?
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06/03/21
Mia J.
your not helping
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06/03/21
Mia J.
i dont unfortunately06/03/21