1. **State the problem:**
We want to compute the surface integral $$\iint_{S} \text{curl} \, \mathbf{F} \cdot d\mathbf{S}$$ where $$\mathbf{F}(x,y,z) = -y^{2} \mathbf{i} + x \mathbf{j} + z^{2} \mathbf{k}$$ and $$S$$ is the part of the paraboloid $$y = 4 - x^{2} - z^{2}$$ inside the cylinder $$x^{2} + z^{2} = 1$$.
2. **Use Stokes' Theorem:**
Stokes' Theorem states:
$$\iint_{S} \text{curl} \, \mathbf{F} \cdot d\mathbf{S} = \oint_{\partial S} \mathbf{F} \cdot d\mathbf{r}$$
where $$\partial S$$ is the boundary curve of surface $$S$$.
3. **Identify the boundary curve $$\partial S$$:**
The boundary is where the paraboloid meets the cylinder:
$$x^{2} + z^{2} = 1$$ and $$y = 4 - x^{2} - z^{2} = 4 - 1 = 3$$.
So the boundary curve is the circle:
$$x^{2} + z^{2} = 1, \quad y = 3$$.
4. **Parametrize the boundary curve:**
Let $$t \in [0, 2\pi]$$,
$$x = \cos t, \quad z = \sin t, \quad y = 3$$.
5. **Compute $$d\mathbf{r}$$:**
$$d\mathbf{r} = \frac{d\mathbf{r}}{dt} dt = (-\sin t \mathbf{i} + 0 \mathbf{j} + \cos t \mathbf{k}) dt$$.
6. **Evaluate $$\mathbf{F}$$ on the boundary:**
$$\mathbf{F}(x,y,z) = -y^{2} \mathbf{i} + x \mathbf{j} + z^{2} \mathbf{k}$$
At boundary:
$$y=3 \Rightarrow y^{2} = 9$$,
$$x = \cos t$$,
$$z = \sin t$$,
so
$$\mathbf{F} = -9 \mathbf{i} + \cos t \mathbf{j} + \sin^{2} t \mathbf{k}$$.
7. **Compute the line integral:**
$$\mathbf{F} \cdot d\mathbf{r} = (-9)(-\sin t) + (\cos t)(0) + (\sin^{2} t)(\cos t) dt = 9 \sin t + \sin^{2} t \cos t \, dt$$.
8. **Integrate over $$t$$ from 0 to $$2\pi$$:**
$$\int_{0}^{2\pi} \left(9 \sin t + \sin^{2} t \cos t \right) dt = \int_{0}^{2\pi} 9 \sin t \, dt + \int_{0}^{2\pi} \sin^{2} t \cos t \, dt$$.
9. **Evaluate each integral:**
- $$\int_{0}^{2\pi} 9 \sin t \, dt = 9[-\cos t]_{0}^{2\pi} = 9(-\cos 2\pi + \cos 0) = 9(-1 + 1) = 0$$.
- For $$\int_{0}^{2\pi} \sin^{2} t \cos t \, dt$$, use substitution:
Let $$u = \sin t$$, then $$du = \cos t dt$$.
When $$t=0$$, $$u=0$$; when $$t=2\pi$$, $$u=0$$.
So integral becomes:
$$\int_{u=0}^{0} u^{2} du = 0$$.
10. **Sum of integrals:**
$$0 + 0 = 0$$.
**Final answer:**
$$\boxed{0}$$
The surface integral of the curl of $$\mathbf{F}$$ over the paraboloid portion inside the cylinder is zero.
Stokes Paraboloid F3Bd3B
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