Question 766994
Try first putting points onto graph paper.  Focus on other side of vertex equally from the directrix.  Focus (-1,-2).  The picture also helps you label the curve and general point (x,y), and set up distance equation knowing the general point is the same distance from focus (-1,-2) as it is from directrix (3,y).


I suggest doing the steps starting from 
{{{sqrt((x-(-1))^2+(y-(-2))^2)=sqrt((x-3)^2+(y-y)^2)}}}

simply becasue putting all the text steps here will be difficult, in contrast to doing it on paper.
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Completing The Square was also needed.
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After the steps and simplifying, you should get something equivalent to


{{{highlight(-(1/8)(y+2)^2=x+1)}}}