SOLUTION: So confused on this! Help would be so appreciated If sec (theta)= -13/5 and 90 degrees < theta < 180 degrees, find the exact value of sin 2(theta)

Algebra ->  Trigonometry-basics -> SOLUTION: So confused on this! Help would be so appreciated If sec (theta)= -13/5 and 90 degrees < theta < 180 degrees, find the exact value of sin 2(theta)      Log On


   

Question 589610: So confused on this! Help would be so appreciated
If sec (theta)= -13/5 and 90 degrees < theta < 180 degrees, find the exact value of sin 2(theta)
Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
If sec (theta)= -13/5 and 90 degrees < theta < 180 degrees, find the exact value of sin 2(theta)
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use x for theta
In quadrant II [90º-180º]
if sec x=-13/5
cos x=-5/13
sin x=12/13
..
sin 2x=2sinx cos x=2*12/13*-5/13=-120/169