Let
and
be a real numbers and let
be a positive integer.
.
Consider
.
Limit of
as
approaches
does not depend on the value of
at
.
The function
.
Now we prove the limit
using
definition.
To show that for each
, there exists a
such that
, whenever
.
Consider 

Consider 

.
Observe the relationship between two absolute values
and
.
inequality is always true irrespective of values of
.
Therefore
then
for any values of
.
Hence
for all values of
.
.