Respuesta :

if you mean cos 3π/6 + 7π/6
then it is cos π/2 + 7π/6
=0+7π/6
=7π/6
And if you mean cos(3π/6 + 7π/6)
=cos(10π/6)
=cos(12π-2π/6)
=cos(2π-π/3)
=cos π/3
=0.5