Trig functions

aami

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Aug 28, 2015
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Hi, I was just wondering if there's a difference in the evaluation between expressions like tan (2pi/3) and tan (-2pi/3)? Or any expressions like that, especially when on the unit circle (or at least in my book), there's no "-2pi/3", only "2pi/3". Thanks.
 
Hi, I was just wondering if there's a difference in the evaluation between expressions like tan (2pi/3) and tan (-2pi/3)? Or any expressions like that, especially when on the unit circle (or at least in my book), there's no "-2pi/3", only "2pi/3". Thanks.
What did you learn when they taught you about the unit circle? Specifically, what kinds of angle measures do you get if you go around the circle more than once, or if you go around backwards? ;)
 
Hi, I was just wondering if there's a difference in the evaluation between expressions like tan (2pi/3) and tan (-2pi/3)? Or any expressions like that, especially when on the unit circle (or at least in my book), there's no "-2pi/3", only "2pi/3". Thanks.

Have learned about co-terminal angle & supplementary angles?
 
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Hi, I was just wondering if there's a difference in the evaluation between expressions like tan (2pi/3) and tan (-2pi/3)? Or any expressions like that, especially when on the unit circle (or at least in my book), there's no "-2pi/3", only "2pi/3". Thanks.

Here they are:
sin(theta) = -sin(-theta)
cos(theta) = cos(-theta)
tan(theta) = -tan(-theta)
 
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