Use a half angle identity to find the exact value cos 165 Which half angle formula should be used to find the exact value of cos 165 Select the correct choice below and fill in the answer boxes to complete your choice Simplify your answer including any radicals Use integers or fractions for any numbers in the expression OA cos 165 cos OB cos 165 cos OC cos 165 cos 5 2 OD cos 165 cos H 2 2 t 2 1 cos 2 1 cos 2 1 cos 1 cos 1 cos 1 cos