ABSTRACT
This chapter aims to presents One-dimensional (1D) problems when the space variable x lies in the axis ℝ. Consider such a 1D stationary problem when the process does not depend on time. Consider 1D stationary heat conduction in the interval. 1D Problems arise also for cylinder symmetry or for spherical symmetry. In some examples, such symmetry is not observed, but the process can be studied locally in the neighbourhood of a point P where the local field can be described by 1D geometry. The chapter also aims to describe the tame infinity in order to understand and properly apply expression. It describes apply physical intuition to model point singularities when the density attains large values.
