I am preparing for my Calculus exam, but am stuck on a question where I need to convert the limit of a Riemann sum to a definite integral.
I usually am able to tackle similar questions, but am stuck on this one. I understand that I need to factor $\Delta{x} = \frac{1}{n}$ out of the expression, giving me
$$ \frac{1}{k + n} = \frac{1}{n}\left(\frac{n}{k + n}\right). $$
However, this is where I am stuck at. I know that in the parentheses, I need to be able to acquire $\frac{k}{n}$ to be the $x$ value also, but I don't see how one can do that from $\frac{n}{k + n}$.
I would appreciate any help or advice pointing me in the right direction.
Thank you so much.