Answer:
[tex]\theta = 120, 240[/tex], in degrees
Step-by-step explanation:
The secant of an angle is given by:
[tex]\sec{\theta} = \frac{1}{\cos{\theta}}[/tex]
In this question:
[tex]\sec{\theta} = -2[/tex]
So
[tex]\frac{1}{\cos{\theta}} = -2[/tex]
[tex]-2\cos{\theta} = 1[/tex]
[tex]\cos{\theta} = -\frac{1}{2}[/tex]
In the first quadrant, the angle that has cosine of 1/2 is 60º.
The cosine is negative in the second and in the third quadrant.
The equivalent angle to 60º in the second quadrant is of 180º - 60º = 120º.
The equivalent angle to 60º in the third quadrant is of 180º + 60º = 240º
So the values of [tex]\theta[/tex] in the interval are:
[tex]\theta = 120, 240[/tex], in degrees