tolong dong kak no 2 & 3, buat besok mepet ni kak butuh bantuan.

yang  no. 2

a. sin 3.000 = sin (8x360 + 120)
sin 3000= sin 120 = sin (180 -60)
sin 3000 = sin 60
sin 3.000 = 1/2 √3

b. cos 2.400 = cos (6x 360 + 240)
cos 2400 = cos 240 = cos (180+60)
cos 2400 = - cos 60
cos 2400 = - 1/2

c. π =180°
sin 5π/4 x tan 7π/4 - (cos 9π)² =
sin 225 x tan 315 - (cos (8π+π))²
sin (180+45) x tan (360-45) - (cos 180)²
= (sin 45)( - tan 45) - (-1)²
= (1/2 √2)(-1)  - 1
= - 1/2√2  -1

d. sin(3π/2) + cos (π/2) / ( 2 tan π/6)
= (sin 270 + cos 45 )/(2 tan 30)
= (-1 + 1/2 √2) / ( 2 (1/√3)
= √3(1 + 1/2 √2) / (2)
= (√3 + 1/2 √6) /(2)
= 1/2 √3 + 1/4 √6

e.  (sin 45 x sin 135 + tan 120)/ (2 sin 60 x cos 30)
= (1/2 √2 x - 1/2 √2) + (-√3)  / (2 (1/2 √3)(1/2 √3)
= (1/2 - √3)/ (3/2)
= 2(1/2 - √3) / (3)
= 2/3 ( 1/2 - √3)
= 1/3  - 2/3 √3