Answer:
[tex]\left ( x-4 \right )^{2}+\left ( y-0 \right )^{2}=\left ( y-2 \right )^{2}[/tex]
Step-by-step explanation: We know that distance from a point on the parabola and focus is equal to their distance from a the directrix. Let (x, y) be the point,
So,
[tex]\sqrt{\left ( x-4 \right )^{2}+\left ( y-0 \right )^{2}}=\frac{\left | y-2 \right |}{1}[/tex]
[tex]\left ( x-4 \right )^{2}+\left ( y-0 \right )^{2}=\left ( y-2 \right )^{2}[/tex]. This is the required equation.