As the engine for producing PDF output.See the Mathematical Notation tutorial for some guidance, especially when rendering online exams.
This is used in both Rnw and Rmd exercises and can be displayed in various ways.
LaTeX is a software system for document preparation, see the corresponding Wikipedia page for an overview. Hence, some useful details are provided that should help R/exams users getting LaTeX installed and used effectively for preparing exams. LaTeX is a document prepration system that is very powerful but can sometimes also be a bit confusing.