Trig help, I have a test tomorrow please help!!!

G

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Guest
I am trying to find which quadrant theta lies in if sin<0 and cos<0, i don't know what to do to figure this out. Please help!!!!
 
In I, all trig functions are positive
In II, the sine is positive.
In III, the tangent is positive. But tan(x)=sin(x)/cos(x), therefore both sine and cosine must be negative.
In IV, cosine is positive.
 
still need help

I already know this but i still don't know how to solve this.

cot>0 and cos>0

I don't know what to do b/c cotangent is not on the ASTC(All, Sine, Tangent, Cosine) quadrant list.
 
Are you telling me that you do NOT KNOW that tan(x) = 1/cot(x)? Does the reciprocal change the sign?

There is a reason why calculators ALWAYS have been built with only THREE trig functions. The user is expected to know some basic information and relationships concerning the other three.
 
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