Maxima and Minima help

[dark swift]

Even though it looks simple, idk how to find the initial height

[timber forum]

initial height is when t = 0

=> x = 5

[dark swift]

ah ok

thanks

yk for the rate of change of x

do I use the first derivative or the 2nd?

[timber forum]

first

[dark swift]

got it

is this all right so far