Hello, im sorry the picture is upside down. But my problem is with this formula: The book i am reading from says the net work done in moving a piston which must push gases, varying the pressure and volume is given by the formula shown in the picture. He then reduces it to what he calls a "cycle integral".I have a few questions/problems: 1.Why, if there are 2 distinct curves present is he using the same equation/ integral for both? 2. surely, if the limits are arranged like so, the whole thing should reduce to zero? this is exactly how the book showed it. Regards, James.