1. **Problem (i): Solve for $0 \leq \theta < 360^\circ$ the equation $9 \sin(\theta + 60^\circ) = 4$.**
2. **Step 1: Isolate the sine function.**
$$\sin(\theta + 60^\circ) = \frac{4}{9}$$
3. **Step 2: Use the inverse sine function to find the principal value.**
$$\theta + 60^\circ = \sin^{-1}\left(\frac{4}{9}\right)$$
Calculate $\sin^{-1}(4/9) \approx 26.3^\circ$.
4. **Step 3: Find the general solutions for $\theta + 60^\circ$.**
Since sine is positive, solutions in $0^\circ$ to $360^\circ$ are:
$$\theta + 60^\circ = 26.3^\circ \quad \text{or} \quad 180^\circ - 26.3^\circ = 153.7^\circ$$
5. **Step 4: Solve for $\theta$.**
$$\theta = 26.3^\circ - 60^\circ = -33.7^\circ$$
$$\theta = 153.7^\circ - 60^\circ = 93.7^\circ$$
6. **Step 5: Adjust $\theta$ to be within $0^\circ \leq \theta < 360^\circ$.**
Add $360^\circ$ to $-33.7^\circ$:
$$\theta = 360^\circ - 33.7^\circ = 326.3^\circ$$
7. **Final answers for (i):**
$$\boxed{\theta = 93.7^\circ, 326.3^\circ}$$
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8. **Problem (ii): Solve for $-\pi \leq x < \pi$ the equation $2 \tan x - 3 \sin x = 0$.**
9. **Step 1: Rewrite the equation.**
$$2 \tan x = 3 \sin x$$
10. **Step 2: Express $\tan x$ as $\frac{\sin x}{\cos x}$.**
$$2 \frac{\sin x}{\cos x} = 3 \sin x$$
11. **Step 3: Multiply both sides by $\cos x$ (noting $\cos x \neq 0$).**
$$2 \sin x = 3 \sin x \cos x$$
12. **Step 4: Rearrange the equation.**
$$2 \sin x - 3 \sin x \cos x = 0$$
$$\sin x (2 - 3 \cos x) = 0$$
13. **Step 5: Solve each factor separately.**
- Case 1: $\sin x = 0$
$$x = 0, \pm \pi$$
Within $-\pi \leq x < \pi$, solutions are $x = -\pi, 0$.
- Case 2: $2 - 3 \cos x = 0$
$$3 \cos x = 2$$
$$\cos x = \frac{2}{3}$$
14. **Step 6: Find $x$ values for $\cos x = \frac{2}{3}$.**
$$x = \pm \cos^{-1}\left(\frac{2}{3}\right)$$
Calculate $\cos^{-1}(2/3) \approx 0.8411$ radians.
15. **Step 7: List all solutions in the interval $-\pi \leq x < \pi$.**
$$x = -0.84, 0, 0.84, -\pi$$
16. **Final answers for (ii) rounded to 2 decimal places:**
$$\boxed{x = -3.14, -0.84, 0, 0.84}$$
Trig Equations 05E577
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