Question

Determine o valor de:
Cos 330

Answer 1

 a) sen 450° = sen(450-360) = sen90 = 1 
b) sen 3TT/2 = sen 3.180/2 = sen 3.90 = sen270 = -1 
c) sen (-390°) = sen(-390+360)= sen -30= -1/2 
e) cos TT/2 = sen180/2 = sen90 = 1 
f) cos 2TT/3= sen2.180/3 = sen 2.60= sen120= sen(180-120)=sen60 = √3/2 
g) cos 330°= -sen(360-330)= -sen30 = -1/2 
h) cos (-1200°= 1200/360=3 + resto120=cos120 = -cos(180-120)=-cos60 = -1/2 >>