In one dimensional motion, instantaneous speed V satisfies $0\le \mathrm{V}<{\mathrm{V}}_0$

By definition, instantaneous velocity, v = dx/dt​

where, x= displacement, T= time

⟹dx = v.dt

⟹x(0) = v₀​(T−0)

⟹x = v₀​T

If the velocity is positive or towards the right of origin, 

Then x = +v₀​T, maximum displacement = +v₀​T

But if the velocity is negative or towards left of origin

Then x = −v₀​T, maximum displacement = −vT

Hence, the displacement x in time T satisfies −v₀​T < x <v ₀​T