1. **State the problem:** Evaluate the improper integral $$I = \int_{e}^{\infty} \frac{dx}{x(\ln x)^3}$$.
2. **Recall the formula and substitution:** For integrals involving $\ln x$, use substitution $t = \ln x$ which implies $dt = \frac{1}{x} dx$ or $dx = x dt$.
3. **Apply substitution:**
$$I = \int_{x=e}^{\infty} \frac{dx}{x(\ln x)^3} = \int_{t=1}^{\infty} \frac{x dt}{x t^3} = \int_{1}^{\infty} \frac{dt}{t^3}$$
4. **Simplify the integral:**
$$\int_{1}^{\infty} t^{-3} dt$$
5. **Integrate:**
Use the power rule for integrals:
$$\int t^n dt = \frac{t^{n+1}}{n+1} + C, \quad n \neq -1$$
Here, $n = -3$, so
$$\int t^{-3} dt = \frac{t^{-2}}{-2} + C = -\frac{1}{2 t^2} + C$$
6. **Evaluate the definite integral:**
$$I = \lim_{b \to \infty} \left[-\frac{1}{2 t^2} \right]_{1}^{b} = \lim_{b \to \infty} \left(-\frac{1}{2 b^2} + \frac{1}{2 \cdot 1^2} \right) = 0 + \frac{1}{2} = \frac{1}{2}$$
7. **Final answer:**
$$\boxed{\frac{1}{2}}$$
This means the integral converges and its value is one half.
Integral Ln Cube 27215D
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