# Summation - Riemann Intergral -

1. Feb 19, 2008

### Mattofix

[SOLVED] Summation - Riemann Intergral - URGENT

1. The problem statement, all variables and given/known data

Im working on the upper and lower riemann sums of f(x) = exp(-x)

where Pn donates the partition of [0,1] into n subintervals of equal length (so that Pn = {0,1/n,2/n,....,1})

2. Relevant equations

3. The attempt at a solution

So far i have the upper sum to be the sum from i=1 to n of exp(-i/n)/n - is this right? - if so where do i go from here? I think im meant to take the limit when n-> infin which should give the final upper sum. I hope this right...

2. Feb 19, 2008

### Mattofix

...and the lower sum to be the sum from i=1 to n of exp((1-i)/n)/n ?