Trig, What would this reduce to?

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Homework Statement



cos(-225)

The Attempt at a Solution



Would it become, -cos45 ?
Just want to make sure.
 
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Are we to assume that this is 225 degrees?

If so then 225= 360- 35, NOT 45.
 
TheRedDevil18, you're correct.

HallsofIvy said:
225= 360- 35
That's not right, it's 225 = 360 - 135.
 

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