![SOLVED: Let (X, d) be a metric space. What is meant by the open ball B(a)? Give the definition of an open set and a closed set in (X, d). Show that SOLVED: Let (X, d) be a metric space. What is meant by the open ball B(a)? Give the definition of an open set and a closed set in (X, d). Show that](https://cdn.numerade.com/ask_images/bd02926d3d84428b9d5746a052359650.jpg)
SOLVED: Let (X, d) be a metric space. What is meant by the open ball B(a)? Give the definition of an open set and a closed set in (X, d). Show that
![Define with examples 1)Finite set,2)Infinite set,3)Universal set,4)singleton set,5)Empty settrip to Korea - Brainly.in Define with examples 1)Finite set,2)Infinite set,3)Universal set,4)singleton set,5)Empty settrip to Korea - Brainly.in](https://hi-static.z-dn.net/files/d85/6d78e0349920b5f3002c340ad0e1250b.jpg)
Define with examples 1)Finite set,2)Infinite set,3)Universal set,4)singleton set,5)Empty settrip to Korea - Brainly.in
![real analysis - Mapping between a finite set and the set of natural numbers - Mathematics Stack Exchange real analysis - Mapping between a finite set and the set of natural numbers - Mathematics Stack Exchange](https://i.stack.imgur.com/u0YyF.png)