The limit of the function is
.
definition of limit :
,
if for every number of
, there exists a
such that
whenever
.
Consider
.

Consider
.

Observe the relation between
and
.
Here
.
definition :
change in
corresponds to
change in
.
Consider
, then
.
Graph :
\Graph of the function
:

Therefore,
change in
corresponds to
change in
.
.