Question

Please, bantu jawabin dong, besok dikumpul
a. cosec (-660°)
b. sin (-1395°)
c. cos 2280°
d. cot (-1845°)

Answer 1

Untuk sudut negatif, maka:
a.
cosec(-660) = -cosec 660
= -cosec (2 x 360 - 60)
= -cosec (-60)
= -(-cosec 60)
= cosec 60
=

b.
sin(-1395) = -sin 1395
= -sin (4 x 360 - 45)
= -sin (-45)
= -(-sin 45)
= sin 45
=

c.
cos 2280 = cos(6 x 360 + 120)
= cos 120
= cos(180-60)
= -cos 60
= -½

d.
cot(-1845) = -cot 1845
= -cot(5 x 360 + 45)
= -cot 45
= -1