The vertex of the parabola is between the shortest line connecting its focus and directrix, so between (0, -4) and y = 4 is the point (0, 0), which is the vertex of the parabola. Also, this parabola faces downward.
The general formula for a parabola that faces downward is y = -4cx^2, where c is the distance from the vertex to either to focus or the parabola. Since c = 4, the equation is y = -16x^2, which is choice A.
<em>The median is the middle point in a dataset half of the data points are smaller than the median and half of the data points are larger. To find the median Arrange the data points from smallest to largest. If the number of data points is odd the median is the middle data point in the list.</em>
3rd one ( not 20 characters so ASHWDHWHEIUCNEJEIH)
2x6 + 4x5 + x4 + 11x3 + 2x2 + 4x + 4