- #1

Trying2Learn

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- TL;DR Summary
- How do we know it is a minumum

The action is the time integral of the Lagrangian - check.

We take the variation of it, and set it to zero - check

But how do we know it is a minimum and not a maximum?

(Don't we formally have to deal with the second variation to be positive?)

Or am I confused? Is it really just important to know it is stationary, and not necessarily a minimum or maximum (and, if so, why?)

We take the variation of it, and set it to zero - check

But how do we know it is a minimum and not a maximum?

(Don't we formally have to deal with the second variation to be positive?)

Or am I confused? Is it really just important to know it is stationary, and not necessarily a minimum or maximum (and, if so, why?)