SOLUTION: if sin of theta is -2/7, and if tan>0, what is the cos of theta?

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Question 954175: if sin of theta is -2/7, and if tan>0, what is the cos of theta?
Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
if sin of theta is -2/7, and if tan>0, what is the cos of theta?
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use x for theta
reference angle theta is in quadrant III where sin<0, cos<0
sinx=-2/7
cosx=-√(1-sin^2(x))=-√(1-4/49)=-√(45/49)=-√45/7