Summation - Riemann Intergral -

[Mattofix]

[SOLVED] Summation - Riemann Intergral - URGENT

Homework Statement

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})

Homework Equations

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 I am meant to take the limit when n-> infin which should give the final upper sum. I hope this right...

 

[Mattofix]

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