SOLUTION: Given that tan theta = 15/8 with theta in quadrant I, find cos 2 theta

Question 876535: Given that tan theta = 15/8 with theta in quadrant I, find cos 2 theta
Answer by lwsshak3(11628) (Show Source): You can put this solution on YOUR website!
Given that tan theta = 15/8 with theta in quadrant I, find cos 2 theta
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Hypotenuse of working reference right triangle in quadrant I=

calculator check:
tan theta=15/8
theta≈61.9275˚
2theta≈123.86˚
cos(2theta)≈cos(123.86˚)≈-0.5572�
Exact value=-161/189≈-0.5571�
let me know if my answer is correct and the method used is understandable
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