Answer:
[(2 + √3)/4] = 0.9330127
Step-by-step explanation:
We know that
cos (pi/12) ^ 2 =
cos (pi/12)* cos (pi/12) =
[(√6 + √2)/4]*[(√6 + √2)/4] =
(0.9659)*(0.9659) = 0.9330127