Discuss the continuity of the cosine, cosecant, secant and cotangent functions.

Explanation

To discuss the continuity of the cosine, cosecant, secant, and cotangent functions, we will analyze each function step by step.

### Step 1: Continuity of Cosine Function
1. **Function Definition**: Let \( f(x) = \cos x \).
2. **Domain**: The domain of \( \cos x \) is all real numbers, i.e., \( (-\infty, \infty) \).
3. **Continuity**: Since \( \cos x \) is defined for all real numbers and is a trigonometric function, it is continuous everywhere in its domain.

### Conclusion for Cosine:
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