Question

a parabola has a vertex at (0,0). the focus of the parabola is located on the positive x - axis. which part of the graph will the directrix pass through?
○ the origin
○ the negative part of the x - axis
○ the positive part of the x - axis
○ the negative part of the y - axis

Explanation:

For a parabola with vertex at \((0,0)\) and focus on the positive \(x\)-axis, the directrix is a vertical line (since the parabola opens horizontally) that is equidistant from the vertex as the focus but in the opposite direction. The focus is on the positive \(x\)-axis, so the directrix will be on the negative \(x\)-axis (e.g., if focus is at \((p,0)\) with \(p>0\), the directrix is \(x = - p\), which is on the negative \(x\)-axis).

Answer:

B. the negative part of the x - axis