The shape of the globe is , where and are in inches.

The bulb is placed at the focus of the parabola.

Since the -term is squared, the parabola is vertical.

Standard form of the vertical parabola is .

Where

Vertex : ,

Focus : ,

Axis of symmetry : ,

Directrix : .

The parabola equation .

Rewrite the equation as .

Compare the above eqation with .

Since , the parabola opens up.

Vertex : ,

Focus : .

The distance from the focus to the vertex : .

Therefore, the bulb should be placed inches from the vertex of the globe.

The bulb should be placed inches from the vertex of the globe.