How to Find the Functional Extremum for Given Boundary Conditions?

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SUMMARY

The discussion focuses on finding the functional extremum for the given boundary conditions using the functional \( S[x(t)] = \int_0^T \left[ \left(\frac{dx(t)}{dt}\right)^{2} + x^{2}(t)\right] dt \). The boundary conditions specified are \( x(0) = 0 \) and \( x(T) = 1 \). Participants emphasize the importance of applying the Euler-Lagrange equations to derive the necessary differential equation for the extremum condition, rather than seeking alternative expressions for the Lagrangian.

PREREQUISITES
  • Understanding of functional calculus and variational principles
  • Familiarity with the Euler-Lagrange equations
  • Knowledge of boundary value problems in calculus
  • Basic concepts of Lagrangian mechanics
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  • Study the derivation and application of the Euler-Lagrange equations
  • Explore examples of functional optimization in physics
  • Learn about boundary value problems and their solutions
  • Investigate the role of Lagrangians in classical mechanics
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Students of physics and mathematics, particularly those studying classical mechanics, variational calculus, and anyone involved in solving boundary value problems.

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Homework Statement


I have been given a functional
$$S[x(t)]= \int_0^T \Big[ \Big(\frac {dx(t)}{dt}\Big)^{2} + x^{2}(t)\Big] dt$$
I need a curve satisfying x(o)=0 and x(T)=1,
which makes S[x(t)] an extremum

Homework Equations



Now I know about action being
$$S[x(t)]= \int_t^{t'} L(\dot x, x) dt$$
and in this equation $$ L= \Big(\frac {dx(t)}{dt}\Big)^{2} + x^{2}(t)$$

The Attempt at a Solution


Is there any other way I can express Lagrangian to fit in this equation and hence I can do the integral? and is there any general solution for the lagrangian?
 
Physics news on Phys.org
Why do you want to do the integral? What is wrong with using the Euler-Lagrange equations? This will give you a differential equation that your solution must satisfy to be an extremum the functional.
 

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