Question

a particle moves along a line so that, at time t, its position is s(t)=8sin2t.
-for what values of t does the particle change direction?

Answer 1

velocity is the derivative of position with respect to time
it changes from sign when it equals zero
so set the derivative of the position function =0
and solve for t

Answer 2

can u show the steps..., i got t=pi/4

Answer 3

and for the next part of the question (what is the particles max velocity), i get the answer as 8, but the answer in the back is 16.

Answer 4

so i would like to know where i went wrong