Write the equation of the parabola with a focus (1,2) and directrix y = 1

Since the y shifted and focus is above directix, parabola opens up
4P(y-k)=(x-h)^2
distance from focus to veretx=distance from vertex to directix=P

from focus to directix is
from 2 to 1 which is 1 distance
1/2=P since 1/2of 1=1/2
4(1/2)(y-k)=(x-h)^2
vertexis 1 higher than directix so add 1/2 to 1 to get 1.5
vertex=(1,1.5)
vertex=(h,k)

equation is
4(1/2)(y-1.5)=(x-1)^2
if you want vertex form
2(y-1.5)=(x-1)^2
divide 2
y-1.5=(1/2)(x-1)^2
add 1.5
y=

If you need an equation, it would be y=2x+8, y would be how long it grew, x being weeks.if you need how long he was asleep, it would be 4 weeks if he started with no beard, the equation would be x=8÷2if he did have a beard before hand, the equation would be 2w+x=8