Solve Cosec Equation 424C12
1. **State the problem:** Solve the equation $$\sqrt{3} \csc\left(2\theta + \frac{3\pi}{4}\right) = 2$$ for $$-\pi < \theta < \pi$$, giving answers in terms of $$\pi$$.
2. **Rewrite the equation:** Recall that $$\csc x = \frac{1}{\sin x}$$, so the equation becomes:
$$\sqrt{3} \cdot \frac{1}{\sin\left(2\theta + \frac{3\pi}{4}\right)} = 2$$
3. **Isolate the sine term:**
$$\frac{\sqrt{3}}{\sin\left(2\theta + \frac{3\pi}{4}\right)} = 2 \implies \sin\left(2\theta + \frac{3\pi}{4}\right) = \frac{\sqrt{3}}{2}$$
4. **Recall sine values:**
$$\sin x = \frac{\sqrt{3}}{2}$$ at
$$x = \frac{\pi}{3} + 2k\pi$$ and $$x = \frac{2\pi}{3} + 2k\pi$$ for any integer $$k$$.
5. **Set up equations:**
$$2\theta + \frac{3\pi}{4} = \frac{\pi}{3} + 2k\pi$$ or
$$2\theta + \frac{3\pi}{4} = \frac{2\pi}{3} + 2k\pi$$
6. **Solve for $$\theta$$:**
For the first:
$$2\theta = \frac{\pi}{3} - \frac{3\pi}{4} + 2k\pi = \frac{4\pi}{12} - \frac{9\pi}{12} + 2k\pi = -\frac{5\pi}{12} + 2k\pi$$
$$\theta = -\frac{5\pi}{24} + k\pi$$
For the second:
$$2\theta = \frac{2\pi}{3} - \frac{3\pi}{4} + 2k\pi = \frac{8\pi}{12} - \frac{9\pi}{12} + 2k\pi = -\frac{\pi}{12} + 2k\pi$$
$$\theta = -\frac{\pi}{24} + k\pi$$
7. **Find all solutions in $$-\pi < \theta < \pi$$:**
For $$\theta = -\frac{5\pi}{24} + k\pi$$:
- If $$k = -1$$, $$\theta = -\frac{5\pi}{24} - \pi = -\frac{5\pi}{24} - \frac{24\pi}{24} = -\frac{29\pi}{24} < -\pi$$ (discard)
- If $$k = 0$$, $$\theta = -\frac{5\pi}{24}$$ (valid)
- If $$k = 1$$, $$\theta = -\frac{5\pi}{24} + \pi = -\frac{5\pi}{24} + \frac{24\pi}{24} = \frac{19\pi}{24}$$ (valid)
For $$\theta = -\frac{\pi}{24} + k\pi$$:
- If $$k = -1$$, $$\theta = -\frac{\pi}{24} - \pi = -\frac{\pi}{24} - \frac{24\pi}{24} = -\frac{25\pi}{24} < -\pi$$ (discard)
- If $$k = 0$$, $$\theta = -\frac{\pi}{24}$$ (valid)
- If $$k = 1$$, $$\theta = -\frac{\pi}{24} + \pi = -\frac{\pi}{24} + \frac{24\pi}{24} = \frac{23\pi}{24}$$ (valid)
8. **Final solutions:**
$$\theta = -\frac{5\pi}{24}, \frac{19\pi}{24}, -\frac{\pi}{24}, \frac{23\pi}{24}$$
These are all solutions in the interval $$-\pi < \theta < \pi$$.
**Answer:** $$\boxed{\theta = -\frac{5\pi}{24}, \frac{19\pi}{24}, -\frac{\pi}{24}, \frac{23\pi}{24}}$$