Find the equation of the parabola described below. Find the two points that define the latus rectum, and graph the equation.
Focus at
So, the equation of the parabola is
Step 1 :Given that the focus is at
Step 2 :The vertex is the midpoint between the focus and the directrix. So, the y-coordinate of the vertex is the average of the y-coordinate of the focus and the y-coordinate of the directrix, which is
Step 3 :The distance from the vertex to the focus or the vertex to the directrix is p. In this case, p is the difference between the y-coordinate of the focus and the y-coordinate of the vertex, which is
Step 4 :Substituting these values into the formula for a vertical parabola, we get
Step 5 :The latus rectum of a parabola is a line segment perpendicular to the axis of symmetry, passing through the focus, and its endpoints lie on the parabola. The length of the latus rectum is
Step 6 :So, the equation of the parabola is