Need help solving the differential equation for the shape of a catenary?

Click For Summary
SUMMARY

The discussion centers on solving the differential equation y''=a*sqrt(1+(y')^2), which represents the shape of a catenary. A suggested approach involves defining a new function u := y' and rewriting the equation as u'/sqrt(1+u^2) = a. This allows for integration of both sides with respect to the appropriate variable. The conversation highlights the importance of understanding the relationship between derivatives and integration in solving differential equations.

PREREQUISITES
  • Understanding of differential equations, specifically second-order equations.
  • Familiarity with calculus concepts, particularly integration and derivatives.
  • Knowledge of the catenary curve and its mathematical representation.
  • Basic skills in manipulating algebraic expressions and functions.
NEXT STEPS
  • Study the method of integrating differential equations using substitution techniques.
  • Learn about the properties and applications of catenary curves in physics and engineering.
  • Explore numerical methods for solving differential equations when analytical solutions are complex.
  • Review calculus concepts, focusing on integration techniques and their applications in differential equations.
USEFUL FOR

Students of mathematics, particularly those studying differential equations, as well as educators and professionals in fields requiring mathematical modeling of physical phenomena.

becksftw
Messages
8
Reaction score
0
(Moderator's note: thread moved from "Differential Equations")

The DE is y''=a*sqrt(1+(y')^2)

I have no idea how to go about integrating it, I just started taking diff eq's and haven't taken calc in over a year. Any help would be appreciated, thanks!
 
Last edited by a moderator:
Physics news on Phys.org
becksftw said:
The DE is y''=a*sqrt(1+(y')^2)

I have no idea how to go about integrating it, I just started taking diff eq's and haven't taken calc in over a year. Any help would be appreciated, thanks!

A first step could be to define a new function u := y'

Then rewrite:

u'/sqrt(1+u^2) = a

and then integrate both sides with respect to time or space or whatever variable y depended on.

Torquil
 

Similar threads

Replies
17
Views
2K
Replies
9
Views
3K
  • · Replies 7 ·
Replies
7
Views
1K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 6 ·
Replies
6
Views
5K
  • · Replies 10 ·
Replies
10
Views
2K
Replies
7
Views
2K
Replies
7
Views
2K
  • · Replies 2 ·
Replies
2
Views
1K