Question

Is there a way to calculate this question using a scientific calculator?

Answer 1

Solution

For this case we know that:

$\sec \theta=2$

Using the definition of sec we have this:

$\frac{1}{\cos \theta}=2$

Then solving for cos we got:

$\cos \theta=\frac{1}{2}$

Then the angle is :

$\theta=arc\cos (\frac{1}{2})=\frac{\pi}{3},-\frac{\pi}{3}$

Then the answer is:

pi/3, -pi/3