8 (1 point) Estimate I = (3x2 + 4x + 5) dx using a Riemann sum, n = 3 subintervals, and 5 + 4 x + 5 ) (a) Left endpoints. IN (b) Right endpoints. IN(1 point) Estimate I = x sin(x)dx using the partition {0, 6' 4' 3 }and 2 (a) Left endpoints. I~ (b) Right endpoints. IN Note: The partition (or subintervals) do not have a constant width