1. **Problem:** Verify Rolle's Theorem for the function $f(x) = e^{-x} \sin x$ on the interval $[0, \pi]$.
2. **Rolle's Theorem states:** If a function $f$ is continuous on $[a,b]$, differentiable on $(a,b)$, and $f(a) = f(b)$, then there exists at least one $c \in (a,b)$ such that $f'(c) = 0$.
3. **Check conditions:**
- $f(x) = e^{-x} \sin x$ is continuous and differentiable everywhere.
- Evaluate $f(0) = e^{0} \sin 0 = 0$.
- Evaluate $f(\pi) = e^{-\pi} \sin \pi = 0$.
4. **Since $f(0) = f(\pi)$, Rolle's Theorem applies.**
5. **Find $f'(x)$:**
$$
f'(x) = \frac{d}{dx} (e^{-x} \sin x) = e^{-x} \cos x - e^{-x} \sin x = e^{-x} (\cos x - \sin x)
$$
6. **Set $f'(c) = 0$:**
$$
e^{-c} (\cos c - \sin c) = 0 \implies \cos c - \sin c = 0 \implies \cos c = \sin c
$$
7. **Solve for $c$:**
$$
\tan c = 1 \implies c = \frac{\pi}{4} \quad \text{(since } c \in (0, \pi)\text{)}
$$
8. **Conclusion:** There exists $c = \frac{\pi}{4} \in (0, \pi)$ such that $f'(c) = 0$, verifying Rolle's Theorem.
Final answer: $c = \frac{\pi}{4}$.
Rolle Theorem B2Efae
Step-by-step solutions with LaTeX - clean, fast, and student-friendly.