SOLUTION: Find the exact value of cos(t/2) if tan(t)= 12/5 and Pie < t < 3pie/2 a)2 Square root of 13/ 13 b)3 Square root of 13/ 13 c)-3/-2 d)None of these e)7 Square root of 13/ 13

Algebra ->  Trigonometry-basics -> SOLUTION: Find the exact value of cos(t/2) if tan(t)= 12/5 and Pie < t < 3pie/2 a)2 Square root of 13/ 13 b)3 Square root of 13/ 13 c)-3/-2 d)None of these e)7 Square root of 13/ 13       Log On


   

Question 928553: Find the exact value of cos(t/2) if tan(t)= 12/5 and Pie < t < 3pie/2
a)2 Square root of 13/ 13
b)3 Square root of 13/ 13
c)-3/-2
d)None of these
e)7 Square root of 13/ 13
Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
Find the exact value of cos(t/2) if tan(t)= 12/5 and Pie < t < 3pie/2
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working with (5-12-13) reference right triangle in quadrant III where cos<0, sin<0
cos(t)=-5/13

note:my ans is the same as that of a) except for the sign.
cost=-5/13
t=247.38˚
t/2=123.69˚ which is in quadrant II where cos<0