Use the Half-angle Formulas to find the exact value of the expression sin 3x 8 Which Half-angle formula should be used to find the exact value of the sin -- (Type an exact answer in terms of x.) ? Select the correct choice below and fill in the answer boxes to complete your che 3x 1+ cos OA. sin sin sin OB. sin 3x -sin =-sin 1-cos 1+ cos OC. sin sin sin 2 OD. sin sin(-)--sin()-- 1 cos -sin =- 2 3x