This is not so much a FAQ as a page of Frequently Brought Up Issues (FBUI?).

• In Project 1 and Project 2 it doesn't matter if you end your lines with semicolons or not. Whether the values are printed doesn't affect the grading software.
• It's good practice to make sure your command are compound commands. For example if you want to calculate sin(cos(55)) and assign it to p7 (I'm making that problem up) you could, in theory, do:

  cos(55)
  sin(ans)
  p7 = ans

  but that's a bit crazy and it's far easier and more sensible to just do:

  p7 = sin(cos(55))

• If you do something like:

  syms x

  and then later if you do something like:

  x = 100

  note that x is no longer symbolic and if you try to use it in an equation later like:

  solve(x^2+x==5)

  you will get an error since x is a constant now and Matlab can't find a variable to solve for.
• There are two videos on youtube related to writing function m-files which I created a few years ago. They may help you figure out what's going on if you're completely lost on Project 3. They are:
  https://www.youtube.com/watch?v=syThKzMAgHs
  and
  https://www.youtube.com/watch?v=5KuALdU4Kw4&t=2s  
• On Project 3, various correct approaches to the problems may produce slightly different answers due to rounding issues which differ from approach to approach. Basically the values should almost be exactly the same but if they differ after the 8th decimal digit that's fine. If they differ earlier then you almost certainly have something not right!
• If you get code complaints about needing .* or ./ or .^ then quite possibly you are using an incorrect command somewhere. Classic example is using

  integral

  when you should be using

  int

  The first does a numerical approximation, which generally you don't want, and requires .*, ./ and .^, but the second does an actual proper integral, and doesn't require those.