Sin 2A Eq
1. **State the problem:** Given the equation $\sin 2A = 2 \sin A$, find the value(s) of $A$.
2. **Recall the double-angle formula for sine:**
$$\sin 2A = 2 \sin A \cos A$$
This formula expresses $\sin 2A$ in terms of $\sin A$ and $\cos A$.
3. **Substitute the formula into the given equation:**
$$2 \sin A \cos A = 2 \sin A$$
4. **Simplify the equation:**
Divide both sides by 2:
$$\sin A \cos A = \sin A$$
5. **Rearrange the equation:**
$$\sin A \cos A - \sin A = 0$$
Factor out $\sin A$:
$$\sin A (\cos A - 1) = 0$$
6. **Solve for $A$ using the zero product property:**
Either
$$\sin A = 0$$
or
$$\cos A - 1 = 0 \implies \cos A = 1$$
7. **Find solutions for $\sin A = 0$:**
$$A = n\pi, \quad n \in \mathbb{Z}$$
8. **Find solutions for $\cos A = 1$:**
$$A = 2n\pi, \quad n \in \mathbb{Z}$$
9. **Combine solutions:**
Since $A = 2n\pi$ is a subset of $A = n\pi$, the complete solution is:
$$A = n\pi, \quad n \in \mathbb{Z}$$
**Final answer:**
$$A = n\pi, \quad n \in \mathbb{Z}$$