Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Multiplier Problem of the Calculus of Variations for Scalar Ordinary
  Differential Equations   In the inverse problem of the calculus of variations one is asked to find a
Lagrangian and a multiplier so that a given differential equation, after
multiplying with the multiplier, becomes the Euler--Lagrange equation for the
Lagrangian. An answer to this problem for the case of a scalar ordinary
differential equation of order $2n, n\geq 2,$ is proposed.

8
The categories of this paper are: hep-ex
15
The categories of this paper are: nucl-ex
31
The categories of this paper are: ao-sci
26
The categories of this paper are: bayes-an
3
The categories of this paper are: physics
33
The categories of this paper are: plasm-ph
21
The categories of this paper are: adap-org
28
The categories of this paper are: alg-geom
24
The categories of this paper are: dg-ga
17
The categories of this paper are: q-fin
20
The categories of this paper are: acc-phys
36
The categories of this paper are: cmp-lg
6
The categories of this paper are: astro-ph
37
The categories of this paper are: supr-con
9
The categories of this paper are: nlin
16
The categories of this paper are: stat