Answer:
try talking about how it made the character feel, and how it changed his/her life badly. maybe they are trying to over come it but keep having flashbacks, and bad memories, but doesn't tell anyone. in the ending, maybe your character can tell someone and get the help they need, before they do something bad to them-selves.
I think you can look at summaries on the internet I have not read the book
A lesson on mathematical formulas given in a doctorate thesis would probably be classified as formal. Thesis, especially the doctorate ones, is classified as formal because this should comply with a certain and strict guidelines for the content as well as meeting the desired requirements given by a particular institution.