limits and velocity?

Question

A particle moves along a straight line with equation of motion s = f(t), where s is measured in meters and t in seconds. Find the velocity and speed when t = 3.
f(t) = t ^-1 - t

velocity= ? m/s
speed= ?m/s

Answer 1

velocity is a vector while speed is the magnitude of this vector
so in this case velocity -10/9m/s means that the speed is 10/9m/s and the velocity is directed in the negative sens

Answer 2

velocity and speed are the same thing
s = f(t) = t^-1 - t
v = f'(t) = - t^-2 - 1
v(3) = - 1/9 - 1 = -10/9 m/s