1. **Problem Statement:**
We are given the graph of the function $y = 2 \ln x$ bounded by the line $y = 2$, the x-axis ($y=0$), and the y-axis ($x=0$). We need to sketch this graph and identify the representative strip for volume calculation when this area is rotated about the x-axis.
2. **Graph and Boundaries:**
- The function is $y = 2 \ln x$.
- The line $y=2$ intersects the curve where $2 \ln x = 2 \Rightarrow \ln x = 1 \Rightarrow x = e$.
- The x-axis is $y=0$.
- The y-axis is $x=0$, but note $\ln x$ is undefined at $x=0$, so the domain is $x>0$.
3. **Representative Strip:**
- To find the volume generated by rotating the area about the x-axis, we consider a vertical strip at position $x$ with thickness $dx$.
- The height of the strip is from $y=0$ to $y=2 \ln x$.
- When rotated about the x-axis, this strip forms a disk with radius $y = 2 \ln x$.
4. **Volume Calculation Formula:**
- The volume of the solid of revolution generated by rotating about the x-axis is given by the disk method:
$$V = \pi \int_a^b [f(x)]^2 dx$$
- Here, $f(x) = 2 \ln x$, and the limits are from $x=1$ (where $y=0$) to $x=e$ (where $y=2$).
5. **Calculate the Volume:**
$$V = \pi \int_1^e (2 \ln x)^2 dx = 4\pi \int_1^e (\ln x)^2 dx$$
6. **Evaluate the integral $\int (\ln x)^2 dx$:**
Use integration by parts:
Let $u = (\ln x)^2$, $dv = dx$.
Then $du = 2 \frac{\ln x}{x} dx$, $v = x$.
$$\int (\ln x)^2 dx = x (\ln x)^2 - 2 \int \ln x dx$$
We know:
$$\int \ln x dx = x \ln x - x + C$$
So,
$$\int (\ln x)^2 dx = x (\ln x)^2 - 2 (x \ln x - x) + C = x (\ln x)^2 - 2x \ln x + 2x + C$$
7. **Apply limits from 1 to $e$:**
At $x=e$:
$$e (\ln e)^2 - 2e \ln e + 2e = e (1)^2 - 2e (1) + 2e = e - 2e + 2e = e$$
At $x=1$:
$$1 (\ln 1)^2 - 2(1) \ln 1 + 2(1) = 0 - 0 + 2 = 2$$
8. **Calculate definite integral:**
$$\int_1^e (\ln x)^2 dx = e - 2 = e - 2$$
9. **Calculate volume:**
$$V = 4 \pi (e - 2)$$
**Final answer:**
$$\boxed{V = 4 \pi (e - 2)}$$
Volume Ln
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