In this article we try to solve the inverse problem of determining
the coe cients of sti ness of the intermediates on the springs on the rod from
the two known natural frequencies. We nd su cient conditions for the exis-
tence of a unique solution to the inverse problem of determining the sti ness
on the intermediates of the springs of non-terminal points of the rod from the
two known natural frequencies. It was shown that for the determination of the
coe cients of sti ness of the springs played an essential role in the geometric
symmetry of the arrangement of the spring relative to the rod center.
