Question 1045382
{{{x=a(y-k)^2+h}}}-------basic standard form, if symmetry axis is horizontal


{{{x=a(y-k)^2}}}--------- no displacement of vertex on x-axis because vertex ON THE y-AXIS


{{{a(y-k)^2=x}}}
{{{a=x/(y-k)^2}}}


{{{system(a=2/(4-k)^2,a=8/(-2-k)^2)}}}-------two given points used to form system; solve for a and k.