1. **State the problem:** Evaluate the definite integral $$\int_0^2 2x \sqrt{x+2} \, dx$$ and verify that it equals $$\frac{32}{15}(2 + \sqrt{2})$$.
2. **Set up the integral:** We have the integral of the function $$f(x) = 2x \sqrt{x+2}$$ from 0 to 2.
3. **Use substitution:** Let $$u = x + 2$$, so that $$du = dx$$ and when $$x=0$$, $$u=2$$; when $$x=2$$, $$u=4$$.
4. **Rewrite the integral in terms of $$u$$:**
$$\int_0^2 2x \sqrt{x+2} \, dx = \int_2^4 2(u-2) \sqrt{u} \, du$$
5. **Expand the integrand:**
$$2(u-2) \sqrt{u} = 2u \sqrt{u} - 4 \sqrt{u} = 2u^{3/2} - 4u^{1/2}$$
6. **Rewrite the integral:**
$$\int_2^4 (2u^{3/2} - 4u^{1/2}) \, du = 2 \int_2^4 u^{3/2} \, du - 4 \int_2^4 u^{1/2} \, du$$
7. **Integrate each term:**
- $$\int u^{3/2} \, du = \frac{u^{5/2}}{\frac{5}{2}} = \frac{2}{5} u^{5/2}$$
- $$\int u^{1/2} \, du = \frac{u^{3/2}}{\frac{3}{2}} = \frac{2}{3} u^{3/2}$$
8. **Substitute back into the integral:**
$$2 \times \frac{2}{5} u^{5/2} - 4 \times \frac{2}{3} u^{3/2} = \frac{4}{5} u^{5/2} - \frac{8}{3} u^{3/2}$$
9. **Evaluate from $$u=2$$ to $$u=4$$:**
$$\left[ \frac{4}{5} u^{5/2} - \frac{8}{3} u^{3/2} \right]_2^4 = \left( \frac{4}{5} 4^{5/2} - \frac{8}{3} 4^{3/2} \right) - \left( \frac{4}{5} 2^{5/2} - \frac{8}{3} 2^{3/2} \right)$$
10. **Calculate powers:**
- $$4^{5/2} = (4^{1/2})^5 = 2^5 = 32$$
- $$4^{3/2} = (4^{1/2})^3 = 2^3 = 8$$
- $$2^{5/2} = (2^{1/2})^5 = (\sqrt{2})^5 = 4 \sqrt{2}$$
- $$2^{3/2} = (2^{1/2})^3 = 2 \sqrt{2}$$
11. **Substitute values:**
$$\left( \frac{4}{5} \times 32 - \frac{8}{3} \times 8 \right) - \left( \frac{4}{5} \times 4 \sqrt{2} - \frac{8}{3} \times 2 \sqrt{2} \right) = \left( \frac{128}{5} - \frac{64}{3} \right) - \left( \frac{16}{5} \sqrt{2} - \frac{16}{3} \sqrt{2} \right)$$
12. **Simplify each group:**
- $$\frac{128}{5} - \frac{64}{3} = \frac{128 \times 3}{15} - \frac{64 \times 5}{15} = \frac{384 - 320}{15} = \frac{64}{15}$$
- $$\frac{16}{5} \sqrt{2} - \frac{16}{3} \sqrt{2} = \left( \frac{16 \times 3}{15} - \frac{16 \times 5}{15} \right) \sqrt{2} = \frac{48 - 80}{15} \sqrt{2} = -\frac{32}{15} \sqrt{2}$$
13. **Combine:**
$$\frac{64}{15} - \left(-\frac{32}{15} \sqrt{2} \right) = \frac{64}{15} + \frac{32}{15} \sqrt{2} = \frac{32}{15} (2 + \sqrt{2})$$
14. **Conclusion:** The value of the integral is $$\boxed{\frac{32}{15} (2 + \sqrt{2})}$$, which matches the given expression.
This confirms the correctness of the integral evaluation.
Integral Evaluation A02157
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