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junemarie15
Nov 28, 2011, 02:17 PM
Find an equation of the parabola that satisfies the given conditionsFocus (6, 0), directrix x = 5

ebaines
Nov 28, 2011, 02:51 PM
Thefiirst "trick" is to recognize that since the directrix is given as x=5 this means the parabola is laying on its side, and so it's form is:

x-x1 = 4p(y-y1)^2

where (x1, y1) are the coordinates for the vertex and p is the distance from focus to vertex, which is also the distance from vertex to directrix. Hence the distance from focus to directrix is two times p. You can determine the distance from focus to directrix from the data you've been given, so you can determine the value of p. Finally, the coordinates of the vertex is half way along the line from focus to directrix. Post back with what you get for an answer and we'll check it for you.