SOLUTION: Cos 280º is equivalent to a)-sin 80º b)cos 10º c)cos 80º d) –cos 80º Answer: c (Just checking to make sure that I did my HW correct) Thanks

Algebra ->  Trigonometry-basics -> SOLUTION: Cos 280º is equivalent to a)-sin 80º b)cos 10º c)cos 80º d) –cos 80º Answer: c (Just checking to make sure that I did my HW correct) Thanks       Log On


   

Question 388938: Cos 280º is equivalent to
a)-sin 80º b)cos 10º c)cos 80º d) –cos 80º
Answer: c (Just checking to make sure that I did my HW correct)
Thanks
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!


Hi, 

Yes! on cos 280° = cos 80°... 

similar to example shown here for cos 300° = cos 60° 

(cosx,sinx)