Nilai sin 195 derajat - Cos 15 derajat adalah

sin(180+15) - cos15
= -sin15 - cos15
= -sin(45-30) - cos(45-30)
= -(sin45 cos30 - cos45 sin30) - (cos45 cos30 + sin45 sin30)
= -[(1/2)√2.(1/2)√3 - (1/2)√2.(1/2)] - [(1/2)√2.(1/2)√3 + (1/2)√2.(1/2)]
= -(1/2)√6