Question

What does the line y=k-1/4a represent in y=a(x-h)^2+k, the standard form of equation for a parabola?

Answer 1

The answer should be the directrix because k represents the y-value of the vertex, and for this questions the parabola is probably facing upward, so the directrix is under the vertex.

Answer 2

Answer:

The line y=k-1/4a represent in y=a(x-h)^2+k is:

                                   Directrix.              

Step-by-step explanation:

Directrix of a parabola--

A directrix is a line which is perpendicular to the axis of symmetry of a parabola and it does not touch the parabola.

Also, for the standard equation of the parabola i.e.

                          $y=a(x-h)^2+k$

The equation of directrix of a parabola is given by:

                    $y=k-\dfrac{1}{4a}$