I have recently started out with series and I have a few set of questions.
Consider, $$\sum\limits_{k=p}^{q} f(k) $$
How is the notation read as? Like summation $k = p $ to $q$ or Sigma $k=p$ to $q$.
Why (I want to know the reason pls) should $k$ always be an integral value?
Can $k$ take negative values like $-3$, $-7$? or fractional values like $ \frac{1}{2} $ etc?
I tried googling but all I found was all sorts of irrelevant or advanced stuffs. Please use laymen terms :)