Parametrising a Curve: Evaluating a Line Integral on a Spherical Intersection

  • Thread starter Thread starter ElDavidas
  • Start date Start date
  • Tags Tags
    Curve
Click For Summary
SUMMARY

The discussion focuses on parametrizing the curve of intersection between two spherical surfaces defined by the equations x² + y² + z² = 4 and x² + y² + (z - 1)² = 2. The user successfully determined that z = 3/2 and derived the equation y = √(7/4 - x²). To fully parametrize the curve, it is essential to recognize the intersection as a circle in the xy-plane with a radius of √(7/4) and a constant z-coordinate of 3/2. The next step involves applying the parametric equations for a circle to express the curve in terms of a parameter.

PREREQUISITES
  • Understanding of spherical equations and their intersections
  • Knowledge of parametric equations for curves
  • Familiarity with basic calculus concepts, particularly line integrals
  • Ability to manipulate algebraic expressions involving square roots
NEXT STEPS
  • Learn how to derive parametric equations for a circle in the xy-plane
  • Study the concept of line integrals in multivariable calculus
  • Explore the application of parametrization in evaluating integrals over curves
  • Investigate the geometric interpretation of intersections between spherical surfaces
USEFUL FOR

Students and professionals in mathematics, particularly those studying calculus and geometry, as well as anyone involved in evaluating line integrals in three-dimensional space.

ElDavidas
Messages
78
Reaction score
0
hi, I'm stuck on a curve parametrisation question. It reads as follows:

"Consider the two spherical surfaces [itex]x^2 + y^2 + z^2 = 4[/itex] and [itex]x^2 + y^2 + (z - 1)^2 = 2[/itex]. Let [itex]\gamma[/itex] be the curve in which they meet. Evaluate the line integral x over gamma "

So far I have let the two surfaces equal one another and found that [itex]z = \frac {3} {2}[/itex]. Then I substituted this back into the equation above and found that [itex]y = \sqrt {\frac {7} {4} - x^2}[/itex].

I don't quite know how to take this further and parametrise the curve between the two spheres.

I'm not sure if this is the right way of doing this. Any help or comments would be appreciated.

Thanks
 
Last edited:
Physics news on Phys.org
You have, in other words
z = 3/2
x^2 + y^2 = 7/4

In a plane parallel to the xy-plane, you can recognize the second equation as a circle with radius sqrt(7/4). And the z-coordinate of this circle is 3/2. Do you know the parametric equation for a circle with a given radius r? That's what you put in your xy-coordinates for the curve. In your z-coordinate you already know what to put.
 

Similar threads

  • · Replies 10 ·
Replies
10
Views
1K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 4 ·
Replies
4
Views
1K
  • · Replies 8 ·
Replies
8
Views
2K
Replies
3
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 9 ·
Replies
9
Views
3K
  • · Replies 4 ·
Replies
4
Views
1K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K