jawablah soal no. 17 di bawah ini dsertai cara krjanya!!!!

sin 150 = sin (180-30) = sin 30 = 1/2
sin 120 = sin (180-60) = sin 60 = √3/2
cos 210 = cos (180+30) = -cos 30 = -√3/2
cos 300 = cos(360-60) = cos 60 = 1/2

(1/2 + √3/2)
-------------------
(-√3/2 - 1/2)

(1/2 + √3/2)
---------------------
-(√3/2 + 1/2)

1/-1 = -1