It is not cumulative but you will be expected to remember background material from before the mid term. Bring a calculator with fresh batteries , you may need to do some arithmetic.
More credit is given for showing the derivation rather than doing arithmetic.
If you do a derivation and make a small small error, the grader can see this, if you just give the answer the grader may not be able to give partial credit if it is wrong. If you are not sure of how to interpret some aspect of a question ask. Answers of common interest will be announced to the entire class. Some problems are suggested in the lecture notes, those are good to try. Recall the papers given out during the class, try to remember the general principles discussed in the papers.