All Questions
3
questions with no upvoted or accepted answers
0
votes
0
answers
67
views
Naming a sum such as $\sum\limits_{x=1}^{n}{x}=\frac{n(n+1)}{2}$
If we let consider a simple sum such as the following:
$$\sum_{x=1}^{n}{x}=\frac{n(n+1)}{2}$$
Would it be correct to name the function that equals $\sum\limits_{x=1}^{n}{x}$ for a given upper bound,...
- 1,619
0
votes
0
answers
201
views
Redefining a Variable in terms of itself vs creating a new one
Suppose I want to show
$$\sum_{n=1}^{\infty}ar^{n-1} = \sum_{n=0}^{\infty}ar^{n}$$
Is it acceptable to increment $n$ by redefining it in terms of itself, i.e., $n = n+1$ (written n+=1 in many ...
- 1,206
-1
votes
2
answers
112
views
What is the difference between the summations?
What is the difference between the summation $$\sum_{1 \leq i<j \leq n} f(i,j)$$ and $$\sum_{1\leq i} \sum_{<j \leq n} f(i,j)?$$
