1. **Stating the problem:**
We want to verify or understand the integral equation:
$$\int \frac{n^2}{\sqrt{27 - n^3}} \, du = -\frac{1}{2} t + c$$
2. **Understanding the integral:**
The integral is with respect to $u$, but the integrand is in terms of $n$. This suggests $n$ is a function of $u$, or there might be a substitution involved.
3. **Rewrite the integral:**
Assuming $n$ is the variable of integration, the integral is:
$$\int \frac{n^2}{\sqrt{27 - n^3}} \, dn$$
4. **Use substitution:**
Let:
$$x = 27 - n^3$$
Then:
$$\frac{dx}{dn} = -3n^2 \implies dx = -3n^2 dn$$
5. **Rewrite $n^2 dn$ in terms of $dx$:**
$$n^2 dn = -\frac{1}{3} dx$$
6. **Substitute into the integral:**
$$\int \frac{n^2}{\sqrt{27 - n^3}} dn = \int \frac{n^2}{\sqrt{x}} dn = \int \frac{1}{\sqrt{x}} \cdot n^2 dn = \int \frac{1}{\sqrt{x}} \cdot \left(-\frac{1}{3} dx\right) = -\frac{1}{3} \int x^{-1/2} dx$$
7. **Integrate:**
$$-\frac{1}{3} \int x^{-1/2} dx = -\frac{1}{3} \cdot 2 x^{1/2} + C = -\frac{2}{3} \sqrt{x} + C$$
8. **Back-substitute $x$:**
$$= -\frac{2}{3} \sqrt{27 - n^3} + C$$
9. **Compare with the right side:**
The given right side is:
$$-\frac{1}{2} t + c$$
This suggests a relationship between $t$ and $n$ such that:
$$-\frac{2}{3} \sqrt{27 - n^3} + C = -\frac{1}{2} t + c$$
or equivalently,
$$t = \frac{4}{3} \sqrt{27 - n^3} + \text{constant}$$
**Final answer:**
$$\int \frac{n^2}{\sqrt{27 - n^3}} \, dn = -\frac{2}{3} \sqrt{27 - n^3} + C$$
Integral Substitution 1Af3F8
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