$\"\"$

The function is $\"\"$ .

Definition : The area A under a function $\"\"$ on $\"\"$ is

$\"\"$

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

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

Width of the rectangle :

$\"\"$

Substitute $\"\"$ and $\"\"$ in the definition of area.

$\"\"$

The area under the graph of $\"\"$ is $\"\"$ .

$\"\"$

The area under the graph of $\"\"$ is $\"\"$ .