Consider f(x) = x^2 and find Riemann sum of f over interval [6,8], using given number of subintervals (n). In every case, select representative points to be left endpoints of subintervals.
(a) Utilize 2 subintervals of equal length (n = 2).
(b) Utilize 5 subintervals of equal length (n = 5).
(c) Utilize 10 subintervals of equal length (n = 10).
(d) Can you guess at area of region under graph of f on interval [6, 8]?