39.8k views
1 vote
Find a vector function that represents the curve of intersection of the paraboloid and the cylinder. Use the variable t for the parameter.

User Kwoxer
by
8.2k points

2 Answers

5 votes

Final Answer:

The vector function that represents the curve of intersection of the paraboloid and the cylinder, using the parameter (t), is given by
\( \mathbf{r}(t) = \langle t, t^2, √(1 - t^2) \rangle \).

Step-by-step explanation:

To find the vector function representing the curve of intersection between the paraboloid and the cylinder, we consider the equations of both surfaces. Let the paraboloid be represented by
\( z = x^2 + y^2 \) and the cylinder by
\( x^2 + y^2 = 1 \). Setting these two equations equal to each other, we get
\( x^2 + y^2 = z \) and
\( x^2 + y^2 = 1 \). These equations describe the intersection curve.

Now, parameterize the curve using a parameter (t) to obtain
\( x(t) = t, \) \( y(t) = t^2, \) and \( z(t) = √(1 - t^2) \). Combining these into a vector function, we have
\( \mathbf{r}(t) = \langle t, t^2, √(1 - t^2) \rangle \). This vector function traces the curve of intersection for different values of (t).

The parameter (t) allows us to trace the curve as (t) varies. The resulting vector function
\( \mathbf{r}(t) \) provides a convenient way to represent the curve in three-dimensional space. It's important to note that this is a specific solution for the given surfaces, and the parameterization may vary for different pairs of surfaces.

User MattOpen
by
8.5k points
2 votes

Final answer:

The student is seeking a vector function that describes the curve of intersection between a paraboloid and a cylinder. Assuming general forms for these surfaces, the vector function for the curve of intersection, when the cylinder is centered about the z-axis, is
\( \vec{r}(t) = \langle r*cos(t), r*sin(t), r² \rangle, where 't' is the parameter and 'r' the radius of the cylinder.

Step-by-step explanation:

Finding a Vector Function for the Curve of Intersection

The student is asking for a vector function that represents the curve of intersection of two surfaces: a paraboloid and a cylinder. Since the equation for each surface is not specified in the question, we'll assume general forms for both. A paraboloid can be represented by z = x² + y², and a cylinder centered around the z-axis can be represented by x² + y² = r², where 'r' is the radius of the cylinder. To find the curve of intersection, we set the equations equal to each other due to the similarity in their x and y terms, which leads to z = r².

To represent this curve with a vector function, we can parametrize it using trigonometric functions for x and y to satisfy the cylinder's equation. By letting x(t) = r*cos(t) and y(t) = r*sin(t), where 't' is the parameter, we consequently have z(t) = r². Therefore, the vector function that represents the curve of intersection is
\( \vec{r}(t) = \langle r*cos(t), r*sin(t), r² \rangle.

To express the answer in a coordinate system with the origin as the center of the cylinder, no further action is necessary because the vector function is already centered around the origin.

User Michael Roswell
by
8.9k points