(a)

Motion of particle is .

Find the velocity of particle by applying derivative.

Therefore the velocity of particle is .

Equate it to zero.

So the critical numbers are and .

(b)

Consider the test intervals to find the interval of increasing and decreasing.

Test interval	Test value	Sign of	Conclusion
		\ \	Increasing
		\ \	Decreasing
		\ \	Increasing

 The sign of the velocity function is positive on the intervals and .

(c)

The sign of the velocity function is negative on the intervals .

(d)

At and , the velocity function changes its sign.

(a) The velocity of particle is .

(b) The sign of the velocity function is positive on the intervals and .

(c) The sign of the velocity function is negative on the intervals .

(d) Velocity function changes its direction at and .