- #1

- 1

- 0

## Homework Statement

How to define closed,, open and compact sets?Are they bounded or not?

## Homework Equations

For example {x,y:1<x<2}

## The Attempt at a Solution

It's is opened as all points are inner

Can you please say the rule for defining the type of the set? Like for example 1<=(x^2+y^2)<=2?