$\"\"$

The limit of the function is $\"\"$ .

Definition :

$\"\"$

means that for every negative number $\"\"$ there is a positive number $\"\"$ such that, if $\"\"$ then $\"\"$ .

To define the infinite limit from left side, replace $\"\"$ by $\"\"$ .

$\"\"$

Consider $\"\"$ .

$\"\"$

Consider $\"\"$ .

$\"\"$

Observe the relation between $\"\"$ and $\"\"$ .

$\"\"$ .

$\"\"$

Verification :

Consider $\"\"$ .

$\"\"$

$\"\"$ .