For reference, saying "in an extended number line" is the equivalent of saying "including infinity".

Like, if it's the real number line, extended real number line means real numbers and infinity and negative infinity.

Infinity isn't a real number, pal. So, I have to qualify it, because you'll say that it's impossible to divide by zero, chief. Unless you have an answer that isn't infinity, friend. I can remove the qualifier if you'd like, and the answer is still technically correct, boss. I am willing to accept I'm wrong if you can answer which number one divided by zero is, I could very well be wrong.

Apologies for my upbeat tone, I'm Canadian, you see, and I believe that we should always use a friendly tone when teaching people new things, ya scamp. I realize this probably comes across to you as arrogant, but I think that might be more related to you thinking I'm wrong when I'm not.