$\"\"$

Observe the graph of the parabola :

The parabola passing through $\"\"$ and $\"\"$ and axis of the parabola is horizontal.

The standard form of the parabola with vertex at $\"\"$ and directrix $\"\"$ is $\"\"$ .

Substitute the point $\"\"$ in $\"\"$ .

$\"\"$

$\"\"$ \ \

$\"\"$ . \ \

The focus of the parabola is $\"\"$ .

Substitute the value $\"\"$ in $\"\"$ .

$\"\"$

The equation of the parabola is $\"\"$ . $\"\"$

The focus of the parabola is $\"\"$ and its equation $\"\"$ .