# General Reimann sum questions

veegeedeejay
I have a homework question which asks about Reimann sums (which I feel relatively comfortable with), but I just don't know what they're asking. Here's the image

https://dl.dropbox.com/u/38457740/maff.bmp [Broken]

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Villyer
For the second one there, what is the sum of all numbers between 1 and n?

veegeedeejay
Thanks for the reply. Found out I'm not following at least a couple rules to the forum, but it wouldn't let me delete my post. :/

40, obviously, is my attempt at problem one, but that was with the help of a teacher (not sure if it's correct yet..)

To answer your question, wouldn't that just be the given part of the problem, condensed to (n^2-n)/2?

Villyer
To answer your question, wouldn't that just be the given part of the problem, condensed to (n^2-n)/2?

Close, but not quite the right formula. The condensed form that they gave is ##\frac{n^2 + n}{2}##, is that what you meant?

veegeedeejay
Whoops, yeah I switched the sign.

Part of what's confusing me is the j=41 under each sigma, where I'm used to seeing 0 or 1. When the function is j or j^2, etc, does this mean that the start point is 41 and 41^2, respectively?

I'm not sure if this even helps me solve the problem, but I'm trying to get a grip on what every variable means here.