The Area of the Region Under The $f ( x ) = \frac { 1 } { 4 + x ^ { 2 } }$

Short Answer

The area of the region under the $f ( x ) = \frac { 1 } { 4 + x ^ { 2 } }$ is defined to be $\int _ { - \infty } ^ { \infty } f ( x ) d x$ Find this area.