Question 1120655
Half the width is 3 feet.  If vertex is origin and dish is concave upward,
Some points on the cross section are  (0,0), (-3,2), and (3,2).
p, distance of focus from vertex in the concave space above vertex


{{{4py=x^2}}}

{{{4p=x^2/y}}}

{{{4p=3^2/2}}}

{{{4p=9/2}}}

{{{p=9/8}}}

{{{highlight(p=1&1/8)}}}