Sin 2X Over Sin X
1. **State the problem:** Simplify the expression $$y = \frac{\sin 2x}{\sin x}$$ and understand its behavior.
2. **Recall the double-angle formula for sine:** $$\sin 2x = 2 \sin x \cos x$$.
3. **Substitute the formula into the expression:**
$$y = \frac{2 \sin x \cos x}{\sin x}$$
4. **Simplify by canceling $$\sin x$$ (assuming $$\sin x \neq 0$$):**
$$y = 2 \cos x$$
5. **Interpretation:** The function simplifies to $$y = 2 \cos x$$, which is a cosine wave with amplitude 2.
6. **Important note:** The original function is undefined where $$\sin x = 0$$, i.e., at $$x = k\pi$$ for integers $$k$$, because division by zero is undefined.
7. **Summary:** The graph of $$y = \frac{\sin 2x}{\sin x}$$ matches the graph of $$y = 2 \cos x$$ except at points where $$\sin x = 0$$, where the function has vertical asymptotes or is undefined.
**Final answer:** $$y = 2 \cos x$$ (for $$x \neq k\pi$$).