How dare you!
I am not a textbook. I do not supply answers, I explain them!
I am not going to answer all questions.
Rather tell you how to do them.
You need to use the inverse-trigonometric functions.
In the first example,
Use the inverse trigonometric function on the calculator,
Therefore you get,
The other value is in the second quadrant,
Note: when you reach a problem like,
Is the same as,
Cuz, secant is reciprocal of cosine.