SOLUTION: If -90°<&#4928;<0° and tan&#4928;=-2/3,What is the value of cos&#4928;?

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Question 1028236: If -90°<ፀ<0° and tanፀ=-2/3,What is the value of cosፀ?
Answer by fractalier(6550) About Me  (Show Source):
You can put this solution on YOUR website!
In quadrant IV, cosine is positive...to find it, you will need to find the hypotenuse...here that would be sqrt(-2*-2 + 3*3) = sqrt(13)...
cos x = adjacent/hypotenuse = 3/sqrt(13) = 3*sqrt(13)/13