Why my comments were deleted from this question? I asked the OP the definition of the principal $n$-th root of $x$, where $x$ is a real number. I exchanged comments with the OP on that.
Moderators often prune obsolete comments and lengthly exchanges to improve the quality of the site. You asked the OP the same question three times in a row and refused his invitation to move your conversation to a chat. You are advised to avoid extended discussion in the comments, and you should be aware that repeated instances of this behaviour may result in a suspension.
Alexander Gruber's answer is quite correct, but since I was the one who deleted most of the comments in question I thought I'd add my reasoning. I deleted the comments for two reasons:
- You were clearly badgering the OP.
- I believed they were a distraction from the question, mostly because you were badgering and being obstinate.
These are standard reasons for deleting comments. Comments are treated as second-class citizens across the SE platform, and are often deleted when they distract from questions or are obsolete.
I did not delete the OP's comment linking to a definition of the principal $n$th root, which I believe was deleted by mistake.
I would also like to discourage you from commenting in this manner in the future. Badgering is not acceptable behavior, and may be considered grounds for a suspension.