Trig Evaluations
1. **Evaluate $\tan(\cos(-\frac{11\pi}{2}))$**
- First, find $\cos(-\frac{11\pi}{2})$.
- Since cosine is an even function, $\cos(-x) = \cos x$, so $\cos(-\frac{11\pi}{2}) = \cos(\frac{11\pi}{2})$.
- Reduce $\frac{11\pi}{2}$ by subtracting multiples of $2\pi$:
$$\frac{11\pi}{2} - 4\pi = \frac{11\pi}{2} - \frac{8\pi}{2} = \frac{3\pi}{2}$$
- So, $\cos(\frac{11\pi}{2}) = \cos(\frac{3\pi}{2}) = 0$.
- Now, $\tan(0) = 0$.
2. **Find the exact value of $\sin(\frac{7\pi}{6})$**
- $\frac{7\pi}{6}$ is in the third quadrant where sine is negative.
- Reference angle is $\frac{7\pi}{6} - \pi = \frac{\pi}{6}$.
- $\sin(\frac{\pi}{6}) = \frac{1}{2}$.
- Therefore, $\sin(\frac{7\pi}{6}) = -\frac{1}{2}$.
3. **Simplify $\cot t \csc t (\sec^2 t - 1)$**
- Recall the identity $\sec^2 t - 1 = \tan^2 t$.
- Substitute: $\cot t \csc t \tan^2 t$.
- Express in terms of sine and cosine:
$$\cot t = \frac{\cos t}{\sin t}, \quad \csc t = \frac{1}{\sin t}, \quad \tan t = \frac{\sin t}{\cos t}$$
- So,
$$\cot t \csc t \tan^2 t = \frac{\cos t}{\sin t} \cdot \frac{1}{\sin t} \cdot \left(\frac{\sin t}{\cos t}\right)^2 = \frac{\cos t}{\sin^2 t} \cdot \frac{\sin^2 t}{\cos^2 t} = \frac{\cos t}{\sin^2 t} \cdot \frac{\sin^2 t}{\cos^2 t}$$
- Simplify numerator and denominator:
$$= \frac{\cos t}{\cos^2 t} = \frac{1}{\cos t} = \sec t$$
**Final answers:**
- $\tan(\cos(-\frac{11\pi}{2})) = 0$
- $\sin(\frac{7\pi}{6}) = -\frac{1}{2}$
- $\cot t \csc t (\sec^2 t - 1) = \sec t$