How dare you!

I am not a textbook. I do not supply answers, I explain them!

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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.