Analysis

[SoLuTioN]

If A is open and B is closed, prove that A\B is open and B\a is closed.

[nooonuii]

ข้อความเดิมเขียนโดยคุณ SoLuTioN

If $A$ is open and $B$ is closed, prove that $A\setminus B$ is open and $B\setminus A$ is closed.

$A^c$ is closed and $B^c$ is open.

$A\setminus B=A\cap B^c$

$B\setminus A=B\cap A^c$

What can we say about the intersection of two open sets?


What can we say about the intersection of two closed sets?

[Best ST]

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