Integral Ln X 98347F
1. The problem is to evaluate the integral $$\int \frac{9}{2} \sqrt{x} \ln x \, dx$$ and match it with one of the given options.
2. Rewrite the integral in a simpler form: $$\int \frac{9}{2} x^{1/2} \ln x \, dx$$.
3. Use integration by parts formula: $$\int u \, dv = uv - \int v \, du$$.
4. Choose $$u = \ln x$$ and $$dv = \frac{9}{2} x^{1/2} dx$$.
5. Then, $$du = \frac{1}{x} dx$$ and $$v = \frac{9}{2} \int x^{1/2} dx = \frac{9}{2} \cdot \frac{2}{3} x^{3/2} = 3 x^{3/2}$$.
6. Apply integration by parts:
$$\int \frac{9}{2} x^{1/2} \ln x \, dx = 3 x^{3/2} \ln x - \int 3 x^{3/2} \cdot \frac{1}{x} dx = 3 x^{3/2} \ln x - 3 \int x^{1/2} dx$$.
7. Evaluate the remaining integral:
$$\int x^{1/2} dx = \frac{2}{3} x^{3/2}$$.
8. Substitute back:
$$3 x^{3/2} \ln x - 3 \cdot \frac{2}{3} x^{3/2} + C = 3 x^{3/2} \ln x - 2 x^{3/2} + C$$.
9. Factor out $$x^{3/2}$$:
$$x^{3/2} (3 \ln x - 2) + C$$.
10. Note that $$3 \ln x = \ln x^3$$, so the expression can be written as:
$$x^{3/2} (\ln x^3 - 2) + C$$.
11. Comparing with the options, the correct answer is option (a): $$x^{3/2} (\ln x^3 - 2) + C$$.