On saddle points of continuous functions on the closed 2-disk (in Ukrainian)

We discuss definitions of regular, critical and saddle points of continuous functions on the plane. Two different definitions of a regular point are given. The example is constructed of a continuous non-negative function on the closed 2-disk $D^2$ which vanishes at its boundary and has exactly two local extrema in $Int{D^2}$ and has no saddle points.