Stage 19 · Sets & Intervals — the Language of Functions
19.5.4 Neighborhood: Around a Point
19.5 Intervals and Neighborhoods: Sets on the Number Line
Point 4 of 5
19.5.4 Neighborhood: Around a Point
Core ideaZero in on a small stretch of width δ around a point a, and that's its neighborhood (a−δ, a+δ).
Module goal. Carry the language of sets onto the number line, using intervals and neighborhoods to capture continuous ranges of numbers neatly — a direct route to the domain of a function