Question 1065967
The definition lets you say  {{{sqrt((x-10)^2+(y-0)^2)=sqrt((x-(-10))^2+(y-y)^2)}}}



Simplify that as much as possible, into whatever form you need.


<a href="https://www.youtube.com/watch?v=M8LGsQMwwj4">Deriving Equation for a Parabola, given focus and directrix - video</a>