Sin120 - sin 30 / cos 225 + cos15 ? Tolong bantu lagi please, kok saya gak dapat jawabannya

beri tanda kurung agar jelas dan pasti. dianggap gini
(sin120 - sin30)/(cos225 + cos15)
= (sin60 - sin30)/(-cos45 + cos(45-30))
= ((1/2)√3 - (1/2))/(-(1/2)√2 + cos45 cos30 + sin45 sin30)
= ((1/2)(√3 - 1) / (-(1/2)√2 + (1/2)(√2)(1/2)√3 + (1/2)(√2)(1/2))
silhakan sederhanakan sendiri, hasil
= √2