Distance, displacement, speed and velocity problem 2

A particle X moves along a straight track, starting from a point O at time . The displacement of X from O at time is , where . Find the time at which X is instantaneously at rest, and hence find the total distance travelled by X between and . A second particle Y moves along another straight track, starting from a point P at time . The acceleration of Y at time is , where . The velocity of Y when it leaves P is . When the velocity of Y is , show that the displacement of X from O is equal to the displacement of Y from P.