problem 3.18

The position of a particular particle as a function of time is given by r⃗ = ( 9.60t⋅i^ + 8.85j^ – 1.00t2⋅k^)m, where t is in seconds.
What is the average velocity of the particle between t=1.00 s and t=3.00 s? Express your answer in terms of the unit vectors i^,j^, and k^.
what is the instantaneous velocity at t=3.00 seconds?