F(x)=1/3(x-3)^2-5 axis of symmetry

Ok so first find the vertex
Which is (3,-5)

So axis of symmetry is always the X value of the vertex

So in this equation it is 3

Ahh hope I helped if you need anymore help just comment down below

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