Week 1: Preliminaries: Real-number. functions and their graphs
The topic Real-number. at the page number 2 of section 1.1 , functions and their graphs at the page number 19 of section 1.3 of recomended book of Boston Thomas, G. B. & Finney, A. R. (2005) Calculus (11edition), Addison-Wesley, Reading, Ma, USA