Find the minimum value taken by the integral expression

Click For Summary
SUMMARY

The discussion focuses on finding the minimum value of the integral expression defined as the integral from 0 to π/2 of the function [(y')^2 - y^2 + 2xy] dx, with boundary conditions y(0) = 0 and y(π/2) = π/2. The solution approach involves applying the Euler-Lagrange equation, leading to the ordinary differential equation y'' + y = x. Participants emphasize the need to solve the homogeneous equation and find a particular solution to apply the boundary conditions effectively.

PREREQUISITES
  • Understanding of calculus, specifically integral calculus
  • Familiarity with differential equations, particularly second-order ODEs
  • Knowledge of the Euler-Lagrange equation in the context of variational calculus
  • Ability to solve boundary value problems
NEXT STEPS
  • Study the method of solving second-order ordinary differential equations
  • Learn about the Euler-Lagrange equation and its applications in calculus of variations
  • Explore techniques for finding particular solutions to differential equations
  • Research boundary value problem-solving strategies for differential equations
USEFUL FOR

Students and professionals in mathematics, particularly those studying calculus, differential equations, and variational methods, will benefit from this discussion.

blueyellow

Homework Statement



find the minimum value taken by the integral expression

integral from 0 to pi/2 [(y')^2]-(y^2)+2xy dx
y(0)=0
y(pi/2)=pi/2


The Attempt at a Solution


using euler lagrange
d/dx(2y')-(-2y+2x)=0
2y''+2y-2x=0
from here I'm stuck
 
Physics news on Phys.org
Now it's just an ordinary differential equation, y''+y=x. To get the most general solution solve the homogeneous part y''+y=0 and then look for a particular solution. Then use the boundary values to fix the constants.
 

Similar threads

  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 18 ·
Replies
18
Views
3K
Replies
1
Views
2K
Replies
2
Views
1K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 10 ·
Replies
10
Views
2K
  • · Replies 14 ·
Replies
14
Views
2K
Replies
3
Views
2K
  • · Replies 15 ·
Replies
15
Views
2K