Question 1060382
Use the definition for Parabola and the Distance Formula.


(x,y) is the same distance from x=-4 as it is from (3,6).  The directrix line is the same as point  (-4,y).


{{{sqrt((x-(-4))^2+(y-y)^2)=sqrt((x-3)^2+(y-6)^2)}}}


{{{sqrt((x+4)^2)=sqrt((x-3)^2+(y-6)^2)}}}


square both sides:
{{{(x+4)^2=(x-3)^2+(y-6)^2}}}


Continue to simplify.