A particle starts moving rectilinearly at time `t = 0` such that its velocity(v) changes with time (t) as per equation –
`v = (t2 – 2t) m//s` for `0 lt t lt 2 s`
`= (–t^(2) + 6t – 8) m//s` for `2 le te 4 s`
(a) Find the interval of time between `t = 0` and `t = 4 s` when particle is retarding.
(b) Find the maximum speed of the particle in the interval `0 le t le 4 s`.
