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If COS X = - 1/3 and x is in quadrant II, answer the following questions:

 

sin(x/2)

 

 

 

 

cos(x/2)

 Apr 25, 2021
 #1
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sin  (x/2)   =      sqrt   [ ( 1 - cos x)  / 2 ]   =  [  (1   - (-1/3) ) / 2 ]  =  sqrt  [ (4/3) / 2 ]  =

 

sqrt [ 4/6]  =  sqrt (4)  /sqrt (6)   =  2  sqrt 6  =  (2/6) sqrt 6  =  sqrt 6 / 3

 

 

 

cos (x/2)  = sqrt [ (1 + cos x) /2 ) ]  =  sqrt [ ( 1   + - 1/3) / 2] =  sqrt  [  (2/3)/2] = sqrt [ 1/3]  =

 

sqrt ( 1 )/ sqrt (3)   =    sqrt (3)/3

 

 

cool cool cool

 Apr 25, 2021

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