Identifying if A is Open or Closed

[kmeado07]

Homework Statement

For the following set, state and justify whether or not it is open or closed.

Homework Equations

A={z| I am z >1}

The Attempt at a Solution

I know the definition of an open set, but I am not sure how to use it to solve this question.

 

[Dick]

What is you definition of open set? Do you know some examples of open sets and why they are open? This shouldn't be that challenging. It's the identical to asking if the set B of all points in the plane with coordinates (x,y) with y>1 is open.