definite integral answer different from Riemann Sum calc
I have to calculate a definite integral using the oh so necessary Riemann Sum.
I first calculated the integral with the fundamental theorem as a check.
The integral is from 1 to 2 of (2+3x^2)dx and it equals 9 according to my calculation.
When I calculated with tv Riemann sum, it equaled 1, so I must have made a mistake.
I started by finding delta x = 1/n and xi = i/n
then I set up the equation to be:
lim of n->inf Sigma i=1 to n of f(i/n) 1/n
Isn't that correct?
I then solved it and got 1 as the answer.
If anybody could help me out that would be great.