The condition is :
\If then
.
Find the value of .
definition of limit :
,
if for every number of , there exists a
such that
whenever
.
Compare the condition, if then
with the
definition of limit.
Here and
.
Consider .
Consider .
.
\
Observe the graph.
\If then
.
From the graph, .
Compare with
.
Therefore .
\
.