https://math2ever.blogspot.com/2017/09/exercise-5a-engineering-mathematics-1.html
Exercise 5B | Engineering Mathematics 1
https://math2ever.blogspot.com/2017/09/exercise-5b-engineering-mathematics-1.html
Note Chapter 5 Vector and Scalar | DBM1013
https://math2ever.blogspot.com/2017/09/note-chapter-5-matrices-dbm1013-session-june-2017.html