tolong ya no 2 dan 3 tentang trigonometri,beserta caranya,saya mohon bantuannya,terima kasih:)

2
a. sin 150 = sin (180 - 30) = sin 30 = 1/2
b. cosec 45 = akar 2
c. tan 330 = (tan 360 - 30) = tan 30 = -1/3 akar 3
d. 5/2phi = 5/2x180 = 450
sin 450 = sin (360 + 90) = sin 90 = 1
e. 5/4phi = 5/4x180 = 225
sin 225 = sin (180 + 45)
= sin180 x cos45 + cos180 x sin45
= 0 x 1/2 akar 2 + (-1) x 1/2 akar 2 = -1/2 akar 2