Hey citcat.

Try breaking the integral into two analytic functions and evaluate the integral for the two parts.

Hint: abs(x-1) = x-1 if x >= 1 or 1-x if x < 1, and note that since there is only one single point with a hole in it [0/0 happens when x = 1 but otherwise it's ok] then you can ignore this issue (since it only happens at one point).