Finding the Arc Length Parameterization of a Vector Function

Click For Summary
SUMMARY

The discussion focuses on finding the arc length parameterization of the vector function r(t) = <(e^t)sin(t),(e^t)cos(t),10e^t>. The derivative r'(t) is calculated as . The magnitude of r'(t) is determined to be sqrt(102)*e^t, leading to the arc length S = sqrt(102)*e^t. The final conclusion emphasizes that the arc length parameterization satisfies the condition |dr/ds|=1, confirming that the differential equation ds/dt=sqrt(102)e^t has been solved correctly.

PREREQUISITES
  • Understanding of vector functions and their derivatives
  • Familiarity with arc length parameterization concepts
  • Knowledge of differential equations
  • Basic calculus, including integration techniques
NEXT STEPS
  • Study the concept of arc length in vector calculus
  • Learn how to derive and solve differential equations
  • Explore the properties of vector functions and their magnitudes
  • Investigate the applications of arc length parameterization in physics and engineering
USEFUL FOR

Students studying calculus, particularly those focusing on vector functions and arc length parameterization, as well as educators looking for examples to illustrate these concepts.

PsychonautQQ
Messages
781
Reaction score
10

Homework Statement


Find the arc length parameterization of r(t) = <(e^t)sin(t),(e^t)cos(t),10e^t>

The Attempt at a Solution


so I guess i'll start by taking the derivative of r(t)...
r'(t) = <e^t*cos(t) + e^t*sin(t), -e^t*sin(t) + e^t*cos(t), 10e^t>

ehh...
now do I do
ds = |r'(t)|dt

and integrate? what then? I don't really understand the question or what I'm trying to do really...
 
Last edited:
Physics news on Phys.org
okay so I found the magnitude of r'(t) and it came out to sqrt(102)*e^t .. integrate with respect to t it stays the same thing.

so S = sqrt(102)*e^t now what?
 
PsychonautQQ said:
okay so I found the magnitude of r'(t) and it came out to sqrt(102)*e^t .. integrate with respect to t it stays the same thing.

so S = sqrt(102)*e^t now what?

Well, then you are done. It would sort of help if you understood the reasons for what you are doing. |dr/ds|=|dr/dt|*|dt/ds|. An arclength parametrization has |dr/ds|=1. You found |dr/dt| to be sqrt(102)e^t. So an arclength parametrization s is a solution to ds/dt=|dr/dt|=sqrt(102)e^t. You just solved that differential equation.
 
Last edited:

Similar threads

Replies
2
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
Replies
1
Views
1K
Replies
3
Views
2K
  • · Replies 7 ·
Replies
7
Views
1K
Replies
4
Views
2K
Replies
5
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K