From the Faculty of Science web site: "Students who miss a final exam due to illness or extreme personal distress and would like to apply for a deferred exam (a.k.a. SD) must report to the Science Information Centre within 48 hours of the missed exam...." Your performance in a course up to the exam is taken into consideration in granting a deferred exam status (for example, failing badly generally means you won't be granted a deferred exam). In Mathematics, generally students sit the next available exam for the course they are taking, which could be several months after the original exam was scheduled.
A student who wishes to view their final exam for pedagogic purposes may initiate this process by filling out the appropriate Mathematics department form. Note that this viewing of a final exam cannot change the grade of a final exam (except in the case of an obvious addition or recording error). Requesting a regrade of a final exam would be done at the university level by initiating a review of assigned standing procedure.