**Q: Which expression completes the fundamental trigonometric identity ? sec(-x)**

**A. -sec x**

B. sec x

C. cos x

D. -cos x

A: This is just a trig identity that should be memorized. For a list of all of the trig identities, you can go to:

http://en.wikipedia.org/wiki/List_of_trigonometric_identities

Or, you can find them listed on many other websites (or even in your text book probably).

You will find that: sec(-x) = sec(x)

So, the correct answer is **B.**

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