6. (10 points) The displacement, in meters, of an object moving in a straight line is given by s(t) = 3t2 + 2t - 3, where t is measured in seconds. (a) (6 points) Find the average velocity over each time period shown below. (i) [1, 1.25]; (ii) [1, 1.1]; (iii) [1, 1.01] (b) (4 points) Use the information in part (a) to find the instantaneous velocity when t = 1