Absolute Maximum
1. **State the problem:** Find the absolute maximum value of the function $f(x) = xe^{-x}$ on the interval $[0,2]$.
2. **Formula and rules:** To find absolute extrema on a closed interval, evaluate the function at critical points inside the interval and at the endpoints.
3. **Find the derivative:**
$$f'(x) = \frac{d}{dx}(xe^{-x}) = e^{-x} - xe^{-x} = e^{-x}(1 - x)$$
4. **Find critical points by setting $f'(x) = 0$:**
$$e^{-x}(1 - x) = 0$$
Since $e^{-x} \neq 0$ for all $x$, we have:
$$1 - x = 0 \implies x = 1$$
5. **Evaluate $f(x)$ at critical points and endpoints:**
- At $x=0$: $$f(0) = 0 \cdot e^{0} = 0$$
- At $x=1$: $$f(1) = 1 \cdot e^{-1} = e^{-1}$$
- At $x=2$: $$f(2) = 2 \cdot e^{-2}$$
6. **Compare values:**
- $f(0) = 0$
- $f(1) = e^{-1} \approx 0.3679$
- $f(2) = 2e^{-2} \approx 2 \times 0.1353 = 0.2706$
7. **Conclusion:** The absolute maximum value on $[0,2]$ is $f(1) = e^{-1}$.
**Answer: A) $e^{-1}$**