The function describes the position of a particle moving along a coordinate line, where is in feet and is in seconds.

(a) Find the velocity and acceleration functions.

:
:

(b) Over what interval is the particle moving in the positive direction? Use inf to represent .

Interval:

(c) Over what interval is the particle moving in the negative direction? Use inf to represent .

Interval:

(d) Over what interval is the particle speeding up? Slowing down? Use inf to represent .

Speeding up:
Slowing down:

You can earn partial credit on this problem.