M N Tan Theta
1. Stating the problem: Given the equation $m \sin\theta = n \sin(\theta + 2)$, find the value of $\frac{m+n}{m-n} \tan \theta$.
2. Use the sine addition formula for $\sin(\theta + 2)$:
$$\sin(\theta + 2) = \sin\theta \cos 2 + \cos\theta \sin 2$$
3. Substitute into the original equation:
$$m \sin\theta = n (\sin\theta \cos 2 + \cos\theta \sin 2)$$
4. Rearrange terms:
$$m \sin\theta = n \sin\theta \cos 2 + n \cos\theta \sin 2$$
5. Group terms containing $\sin\theta$ and $\cos\theta$:
$$m \sin\theta - n \sin\theta \cos 2 = n \cos\theta \sin 2$$
6. Factor out $\sin\theta$ on the left:
$$\sin\theta (m - n \cos 2) = n \cos\theta \sin 2$$
7. Divide both sides by $\cos\theta (m - n \cos 2)$:
$$\frac{\sin\theta}{\cos\theta} = \frac{n \sin 2}{m - n \cos 2}$$
8. Recognize that $\frac{\sin\theta}{\cos\theta} = \tan\theta$:
$$\tan\theta = \frac{n \sin 2}{m - n \cos 2}$$
9. Find $\frac{m+n}{m-n} \tan\theta$ substituting for $\tan\theta$:
$$\frac{m+n}{m-n} \tan\theta = \frac{m+n}{m-n} \cdot \frac{n \sin 2}{m - n \cos 2}$$
10. Simplify the denominator $m - n \cos 2$ by writing expression explicitly, or leave as is since no further simplification is indicated.
Hence the final answer is:
$$\frac{m+n}{m-n} \tan \theta = \frac{n (m+n) \sin 2}{(m-n)(m - n \cos 2)}$$