SOLUTION: find the exact value of sin2x given cosx=-12/13 and x is in quadrant 3

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Question 556458: find the exact value of sin2x given cosx=-12/13 and x is in quadrant 3
Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
find the exact value of sin2x given cosx=-12/13 and x is in quadrant 3
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in quadrant 3
cosx=-12/13
sin^2x=1-cos^2x=1-144/169=169/169-144/169=25/169
sinx=√(25/69)=-5/13
sin 2x=2sinx cosx=2*-5/13*-12/13=120/169