Ok so I am a bit confused by the shell method. My prof has given us a general forumula for using the shell method which I understand

where is the line which to rotate around, is the upper curve, and is the lower curve.

When presented with the following question where we have to rotate about as shown on the following graph when I simply substituted 5 in for M, giving me for the first part I get the wrong answer but gives me the correct the answer.

Looking at some of the examples I have it would appear that if the axis of rotation is to the right of our functions it reverses the order of to . Is this correct to assume?