Inactive Tutor answered 03/31/13
The plot of |x| in quadrant 1 is a straight line with slope 1 from the origin to X. In quadrant 2 the plot is a straight line with slope -1 from the origin to -X. The domain is [-X, 0) and [0, X]. The integral of |x| is -(1/2)x^2 in quadrant 2 and (1/2)x^2 in quadrant 1.