$\"\"$

The expression is $\"\"$ .

The expression represents the derivative of the function.

Limit definition of derivative of a function at a number $\"\"$ is $\"\"$ .

Compare the limit expression with above definition.

Here the value of $\"\"$ is $\"\"$ and the function is $\"\"$ .

Similarly, $\"\"$ .

$\"\"$

$\"\"$ and $\"\"$ .