Respuesta :

Answer:

Ф= 111.06° = 0,617π rad

Step-by-step explanation:

sec(Ф) = 1/cos(Ф)

1/cos(Ф) = -2.782

cos (Ф) = -0.3594

Ф= arcos (-0.3594)

Ф = 111.06° * (π/180) = 0,617π radians.