Math, Mathematics, Science, Numerical Analysis, Integration.
the total area of the region or the value of integration is (with a few error): Using the summation notation, we obtain: In the 1st line, we have summed up to n-1, because at r = n-1, f(a+(r+1)h)=f(b), which should be. For the 2nd line, as the middle terms (f(a+h),f(a+2h),..etc exist in 2