I'm pretty sure that's just a polygonal path (straight-line) path from the points . Looks pretty messy too.
If I calculate an antiderivative:
and then use this to calculate the other integral, I get for the first leg:
Maybe easier way though.
As you can see from the checkmarks I already got 6a and 4
If someone could just help me with the notation on 1, like what do those (+) things mean?
original link: http://www.math.ualberta.ca/~runde/files/ass411-2.pdf