Questions: 9. Proponga una parametrización, de una de las dos curvas, que se forma por la intersección de las superficies Σ₁=(x, y, z) x²+y²=6 y Σ₂=(x, y, z) x²+y²+z²=16. No pierda de vista que en unas ecuaciones paramétricas es indispensable indicar el intervalo de variación del parámetro.
Transcript text: 9. Proponga una parametrización, de una de las dos curvas, que se forma por la intersección de las superficies $\Sigma_{1}=\left\{(x, y, z) \mid x^{2}+y^{2}=6\right\}$ y $\Sigma_{2}=\left\{(x, y, z) \mid x^{2}+y^{2}+z^{2}=16\right\}$. No pierda de vista que en unas ecuaciones paramétricas es indispensable indicar el intervalo de variación del parámetro.
Solution
Solution Steps
Step 1: Define the Surfaces
We have two surfaces defined as follows:
The cylinder \(\Sigma_{1} = \{(x, y, z) \mid x^{2} + y^{2} = 6\}\) describes a circular cylinder with radius \(\sqrt{6}\) along the z-axis.
The sphere \(\Sigma_{2} = \{(x, y, z) \mid x^{2} + y^{2} + z^{2} = 16\}\) describes a sphere with radius 4 centered at the origin.
Step 2: Parametrize the Cylinder
To find the intersection, we can parametrize the circular cross-section of the cylinder using the angle parameter \(\theta\):
\[
x = \sqrt{6} \cos(\theta), \quad y = \sqrt{6} \sin(\theta)
\]
where \(\theta\) varies from \(0\) to \(2\pi\).
Step 3: Substitute into the Sphere's Equation
Next, we substitute the expressions for \(x\) and \(y\) into the equation of the sphere to find \(z\):
\[
z = \sqrt{16 - (x^{2} + y^{2})}
\]
Substituting \(x^{2} + y^{2} = 6\):
\[
z = \sqrt{16 - 6} = \sqrt{10}
\]
Step 4: Write the Complete Parametrization
The complete parametrization of the curve formed by the intersection of the two surfaces is given by:
\[
\begin{align_}
x(\theta) &= \sqrt{6} \cos(\theta) \\
y(\theta) &= \sqrt{6} \sin(\theta) \\
z(\theta) &= \sqrt{10}
\end{align_}
\]
for \(\theta \in [0, 2\pi]\).
This describes a circle in the plane \(z = \sqrt{10}\) with radius \(\sqrt{6}\).