I have to find a tight bound for an algorithm.
I ended up with $3n^2 + 5$ as the worst running time of the piece of code.
Is it ok if I consider $n^2$ as the tight bound? $$3n^2 + 5 \in \Theta(n^2)$$
My justification is the following: $$3n^2 \le 3n^2 + 5 \le 8n^2$$
I would agree that reasoning. Intuitively I would ignore any addition or multiplication of scalars from the bound.