1. The problem is to evaluate the integral $$\int \frac{\sin(e^{-x})}{2e^x} \, dx$$.
2. We consider using substitution (u-substitution) to simplify the integral.
3. Let $$u = e^{-x}$$. Then, $$\frac{du}{dx} = -e^{-x} = -u$$, so $$du = -u \, dx$$ or $$dx = \frac{du}{-u}$$.
4. Rewrite the integral in terms of $$u$$:
$$\int \frac{\sin(u)}{2e^x} dx$$.
5. Since $$u = e^{-x}$$, then $$e^x = \frac{1}{u}$$.
6. Substitute $$e^x = \frac{1}{u}$$ and $$dx = \frac{du}{-u}$$:
$$\int \frac{\sin(u)}{2 \cdot \frac{1}{u}} \cdot \frac{du}{-u} = \int \frac{\sin(u)}{2/u} \cdot \frac{du}{-u} = \int \frac{\sin(u) \cdot u}{2} \cdot \frac{du}{-u}$$.
7. Cancel $$u$$ in numerator and denominator:
$$\int \frac{\sin(u) \cancel{u}}{2} \cdot \frac{du}{-\cancel{u}} = \int \frac{\sin(u)}{2} \cdot (-1) du = -\frac{1}{2} \int \sin(u) du$$.
8. Integrate $$\sin(u)$$:
$$\int \sin(u) du = -\cos(u) + C$$.
9. Substitute back:
$$-\frac{1}{2} (-\cos(u)) + C = \frac{1}{2} \cos(u) + C = \frac{1}{2} \cos(e^{-x}) + C$$.
Final answer:
$$\boxed{\frac{1}{2} \cos(e^{-x}) + C}$$
Integral Sin E X Cde8A1
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