Question

faltei a aula de trigonometria e nao sei a materia...
Determine o valor de: a) sen 19 pi radiano/ 4 b) sen 675 grau c) cos 2 pi radiano/3.

Answer 1

 π=180°
 sen19 π/4 =sen19.180/4 =sen855 °
a)855 =2.360° +135°  ,sen855° =sen135°=-√2/2
b)675 =1.360 +315  , sen675=sen315°  =-√2/2
c)cos2π/3=cos2.180/3 =cos120 =-1/2