1. **State the problem:** Find the general solution of the differential equation $$y' = \ln x$$.
2. **Recall the formula:** Since $$y' = \frac{dy}{dx}$$, the equation means $$\frac{dy}{dx} = \ln x$$.
3. **Integrate both sides:** To find $$y$$, integrate $$\ln x$$ with respect to $$x$$:
$$y = \int \ln x \, dx + C$$
where $$C$$ is the constant of integration.
4. **Use integration by parts:** Recall the formula:
$$\int u \, dv = uv - \int v \, du$$
Let:
- $$u = \ln x \implies du = \frac{1}{x} dx$$
- $$dv = dx \implies v = x$$
5. **Apply integration by parts:**
$$\int \ln x \, dx = x \ln x - \int x \cdot \frac{1}{x} dx = x \ln x - \int 1 \, dx$$
6. **Simplify the integral:**
$$\int 1 \, dx = x$$
So,
$$\int \ln x \, dx = x \ln x - x + C$$
7. **Write the general solution:**
$$y = x \ln x - x + C$$
This is the general solution to the differential equation $$y' = \ln x$$.
General Solution 856686
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