y = 1/2x^2-x + 3 for 0_<x_<6.
(b) Calculate the mid-ordinates of 5 strips between x = 1 and x = 6, and hence use the mid- ordinate rule to approximate the area under between x = 1, x = 6 and the x-axis.
(c) Assuming that the area determined by integration to be the actual area, calculate the percentage error in using the mid-ordinate rule.