SOLUTION: Suppose sin(t)=-3/4 amd sec(t)<0. Use identities cos(-t) why does (t) become positive instead of negative? I don't understand this idea at all. Please help Thank you

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Question 962223: Suppose sin(t)=-3/4 amd sec(t)<0. Use identities
cos(-t) why does (t) become positive instead of negative? I don't understand this idea at all.
Please help
Thank you
Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
Suppose sin(t)=-3/4 amd sec(t)<0. Use identities
cos(-t) why does (t) become positive instead of negative? I don't understand this idea at all.
***
I'm not sure what your question is, but my guess it is something about the following Identity:
cosx=cos(-x)
The cos function is always positive whether the angle is in quadrant I or quadrant IV, or the right half of the unit circle. Its negative in the left half of the unit circle.
Similarly, the sin function is positive in the top half and negative in the bottom half of the unit circle.
hope I answered your question.