x y Directrix {{ s1_dist.toFixed(1) }} {{ s1_dist.toFixed(1) }} Focus p = {{s2_p}} p = {{s2_p}} y = {{s3_dirBox}} (0, {{s3_focusBox}})
Drag the point

A parabola is all points that are equidistant from a fixed point (Focus) and line (Directrix).

1
Explore the left side
2
Explore the right side
Adjust the slider

The distance from the vertex to the focus is .

Make to continue.

12345
Match the parts

Find the Focus and Directrix of:

Hint:

Focus
{{ s3_focusBox !== null ? `(0, ${s3_focusBox})` : 'Drop here' }}
Directrix
{{ s3_dirBox !== null ? `y = ${s3_dirBox}` : 'Drop here' }}
{{ token.label }}
Build the equation

Write the equation for the dashed parabola shown above.

1
{{s4_denom}}

Mastered!

You understand how the focus and directrix define a parabola.

{{ s3_draggedToken.label }}