Not sure what this question is asking me, when their is no numbers to calculate, can someone please explain this to me

If Cos(x)=m then what is the value of Cos (180-x)?

Thanks

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- Feb 10th 2010, 02:55 PMnuckersSine and Cosine
Not sure what this question is asking me, when their is no numbers to calculate, can someone please explain this to me

If Cos(x)=m then what is the value of Cos (180-x)?

Thanks - Feb 10th 2010, 03:03 PMdanielomalmsteen
$\displaystyle \cos(a-b) = \cos a \cos b + \sin a \sin b$

- Feb 10th 2010, 03:12 PMicemanfan
It's a trigonometric identity.

cos(180 - x) is always the opposite of cos(x).

You could come to that conclusion several ways, but the easiest method is to look at a typical angle Q on a graph and compare it with its supplement (which is defined as 180 - Q), and then you will see why the conclusion is true. - Feb 10th 2010, 03:25 PMnuckers
- Feb 10th 2010, 03:31 PMicemanfan
- Feb 10th 2010, 03:31 PMskeeter
- Feb 10th 2010, 03:33 PMnuckers