I'm taking differential calculus, and today I had an exam about limits. I came across this problem; the professor marked my answer wrong and explained that what I should have done was take the square root of each term to arrive at the result. When he told me that, I thought, "Oh, okay," but when I got home to continue studying, I found that it is not actually correct to distribute the root in the sum and that it can only be done in a multiplication and division.
I don't know much about math theory and I wouldn't want to question my teacher's knowledge, so if someone could clear up my doubt about the correct procedure, it would help me a lot because tomorrow I have another exam on this same topic!
EDIT: today 29/OCT I was supposed to have my second exam, I was planning to question him about this today but the professor didn't show up (as usual lmao). I won't have class until 03/NOV so I'll question him next Tuesday
