Focus `S-=(6,0)`
and directrix `x=-6" "rArr" "x+6=0`
Let P(x,y) be a variable point on the parabola.
`:.` Distance of from focus S
= Perpendicular distance from P to the directrix.
`rArrsqrt((x-6)^(2)+(y-0)^(2)=x+6)`
`rArr" "(x-6)^(2)+y^(2)=(x+6)^(2)`
`rArr" "y^(2)=24x`