The function
has a finite limit,
, as
. This means that for any
, there is an interval of width
around
(perhaps with
and
very small), such that
whenever
is in that interval. Move the point directly and adjust
using the slider. This Demonstration computes the largest
and
for a given
so that
lies between
and
. The values for
and
may be found automatically or manually by dragging. The function shown is
.
