SOLUTION: 2 cos ^2 6 is identical to : a) 1- cos 12 b) 1 + cos 12 c) 1+ cos 3 d) 1/2 sin ^2 6

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Question 824322: 2 cos ^2 6 is identical to :
a) 1- cos 12
b) 1 + cos 12
c) 1+ cos 3
d) 1/2 sin ^2 6
Answer by Edwin McCravy(20060) About Me  (Show Source):
You can put this solution on YOUR website!
2cosē(6)

We use the identity 

cos(2q) = 2cosē(q)-1

We substitute 6 for q

cos(2·6) = 2cosē(6)-1

cos(12) = 2cosē(6)-1

Add 1 to both sides:

1+cos(12) = 2cosē(6)

Edwin