Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On Jacobi's condition for the simplest problem of calculus of variations
  with mixed boundary conditions   The purpose of this paper is the extension of Jacobi's criteria for positive
definiteness of second variation of the simplest problems of calculus of
variations subject to mixed boundary conditions. Both non constrained and
isoperimetric problems are discussed. The main result is that Jacobi's
condition remains valid also for the mixed boundary conditions.

19
The categories of this paper are: eess
18
The categories of this paper are: econ
17
The categories of this paper are: q-fin
12
The categories of this paper are: nucl-th
35
The categories of this paper are: mtrl-th
20
The categories of this paper are: acc-phys
9
The categories of this paper are: nlin
3
The categories of this paper are: physics
8
The categories of this paper are: hep-ex
36
The categories of this paper are: cmp-lg
4
The categories of this paper are: cond-mat
23
The categories of this paper are: solv-int
33
The categories of this paper are: plasm-ph
29
The categories of this paper are: funct-an
0
The categories of this paper are: hep-ph
11
The categories of this paper are: hep-lat