Good night, I'm trying this exercise:
Let $C\subset\mathbb{R}^n$ connected and let $x$ be an accumulation point of $C$. Prove that $C\cup\{x\}$ is connected.
I understand the exercise, geometrically at least, it makes a lot of sense but no luck trying to prove it, by previous examples, I get that, the idea of working with contentedness is by contradiction using the disjoint sets that their union are the disconnected set, but I can't get to use the definition of accumulation point in my proof, any hints or ideas would be appreciated, thanks.
Suppose that $C\cup\{x\}$ is not connected and take $A\cup B$ a separation of $C\cup\{x\}$. As $C$ is connected then $C$ is contained in some part of the separation, say $A$. As $B$ is open and $x$ an accumulation point, what can you conclude?