OPEN & CLOSED SETS #open #closed #sets
OPEN & CLOSED SETS In this session we see open & closed sets with their properties. OPEN SET : - A non empty set A in the real line R is called an open set , every point in A is an interior point of A. Examples:- * (a, b) is an open set. * [a, b] is not open since the end points a, b are not interior points. * Every finite set is not open. * The sets N, Z and Q are not open sets. * The set R of all real numbers is open. * The set of complex numbers |z|<1 is open. * The set of complex numbers |z| ≤1 is not open. * Every neighbourhood is an open set. Properties of open sets:- 1. Every open set is a union of open intervals. 2. Union of two open sets is open. 3. Intersection of two open sets is ...