SOLUTION: Please help me solve this question: Find the exact value of cos(u+v) given that sinu=7/25 and cosv=-12/13. (Both u and v are in Quadrant II.)

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Question 746198: Please help me solve this question: Find the exact value of cos(u+v) given that sinu=7/25 and cosv=-12/13. (Both u and v are in Quadrant II.)
Answer by savvyhush23(50) About Me  (Show Source):
You can put this solution on YOUR website!
Please help me solve this question: Find the exact value of cos(u+v) given that sinu=7/25 and cosv=-12/13. (Both u and v are in Quadrant II.)
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use arcsin and arccos to find the angle u and v.
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for u: u=sin%5E-1%287%2F25%29=16.26
for v: v=cos%5E-1%28-12%2F13%29=157.38
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but both must be in Quadrant II.
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the values of u that gives sin(u)=7/25 are 16.26 and (180 - 16.26 = 163.74)
therefore, u = 163.74 and v = 157.38
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Finally, cos(163.74 + 157.38) = 253/325 or 0.77846