Question 983230
-1/40 x^2= y


-(1/40)x^2=y


{{{-(1/40)x^2=y}}}  or as {{{x^2=-40y}}} or still equivalently  {{{highlight_green(-40y=x^2)}}}.


Compare that green outlined equation to the basic form,  {{{4p=x^2}}}.


A video which explains this well  (but a little bit clumsy) is this one:
<a href="https://www.youtube.com/watch?v=M8LGsQMwwj4">Equation Derivation for Parabola from Focus and Directrix</a>