SOLUTION: Without using a calculator determine if each function is poositive or negative a) sin 145 degrees b) cos 160 degrees c) cos 210 degrees d) sin 255 degrees e) cos 355 degrees

Question 857580: Without using a calculator determine if each function is poositive or negative
a) sin 145 degrees
b) cos 160 degrees
c) cos 210 degrees
d) sin 255 degrees
e) cos 355 degrees
Can you please help ? Thanks so much in advance:)
Answer by Alan3354(69443) (Show Source): You can put this solution on YOUR website!
Without using a calculator determine if each function is poositive or negative
a) sin 145 degrees
b) cos 160 degrees
c) cos 210 degrees
d) sin 255 degrees
e) cos 355 degrees
---------------------
Check the quadrants.
a) sin 145 degrees Q2 --> +
b) cos 160 degrees Q2 --> -
c) cos 210 degrees Q3 --> -
d) sin 255 degrees Q3 --> -
e) cos 355 degrees Q4 --> +
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Do you know how that works? You don't need to memorize it.

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