Definition :

If $\"\"$ be the function is defined on $\"\"$ then $\"\"$ ,

it means that for every $\"\"$ there is a corresponing number $\"\"$ such that if $\"\"$ then $\"\"$ .

The function is $\"\"$ .

From the definition,

If $\"\"$ then $\"\"$ .

Consider $\"\"$ for $\"\"$ .

Then $\"\"$ since $\"\"$ .

$\"\"$

Therefore from the definition, $\"\"$ .

$\"\"$ .