I have found part a) which is 4d(x-3x)/27 + 2d(x-3/2)/9 + 2d(x+3/2)/27. Note d is delta.
I have also found b) where c=9/26. However i can't figure out c) at all, i know when x<3/2 the cumulative is 0 and when x>=2 the cumulative is 1. I've tried to use past examples given but nothing outlines the method to find it. Any help would be appreciated. Thank you