5. Determine the exact value for the following: (5 marks) \[ \sin \frac{11 \pi}{6} \sec \frac{2 \pi}{3}+\tan \frac{5 \pi}{4} \]
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To solve \( \sin \frac{11 \pi}{6} \sec \frac{2 \pi}{3}+\tan \frac{5 \pi}{4} \), we first calculate each trigonometric function step by step. 1. **Calculate \( \sin \frac{11 \pi}{6} \)**: \[ \sin \frac{11 \pi}{6} = -\frac{1}{2} \quad (\text{since it's in the fourth quadrant}) \] 2. **Calculate \( \sec \frac{2 \pi}{3} \)**: \[ \sec \theta = \frac{1}{\cos \theta} \] Since \( \frac{2 \pi}{3} \) is in the second quadrant, we have: \[ \cos \frac{2 \pi}{3} = -\frac{1}{2} \implies \sec \frac{2 \pi}{3} = -2 \] 3. **Now, substitute into the expression for \( \sin \frac{11 \pi}{6} \sec \frac{2 \pi}{3} \)**: \[ \sin \frac{11 \pi}{6} \sec \frac{2 \pi}{3} = \left(-\frac{1}{2}\right)(-2) = 1 \] 4. **Calculate \( \tan \frac{5 \pi}{4} \)**: \[ \tan \frac{5 \pi}{4} = 1 \quad (\text{since } \tan \theta = \frac{\sin \theta}{\cos \theta} \text{ and both sine and cosine are negative in the third quadrant}) \] 5. **Add the two results together**: \[ \sin \frac{11 \pi}{6} \sec \frac{2 \pi}{3} + \tan \frac{5 \pi}{4} = 1 + 1 = 2 \] Thus, the final result is: \[ \boxed{2} \]