Question

The equation of the directix of the parabola whose vertex $(3,2)$ and focus $(2,-1)$ is

• A. $x+3y-19=0$
• B. $y+2y-9=0$
• C. $2x+6y-24=0$
• D. $x-3y-19=0$

Answer 1

Answer: (A)

$x+3y-19=0$

the line passing through the vertex$(3,2)$ and focus $(2,-1)$ should be perpendicular to the directix of the parabola (as per the defination )

the equation of line passing through the focus and vertex is => $y-3x+7=0$;

as you can see only option $A$ has a line perpendicular to this line.