(1 point) Consider the function f (I) = 3 + 6. In this problem you will calculate 3 + 6 dx by using the definition f(x) dx = lim 12 +00 The summation inside the brackets is R, which is the Riemann sum where the sample points are chosen to be the right-hand endpoints of each sub-interval. Calculate Rn for f(x) = 3 + 6 on the interval [0, 4) and write your answer as a function of n without any summation signs. You will need the summation formulas 1+2+3+ . . . +n= I'M i n(n + 1) n- +n 2 2 12 + 22 + 32+ ...+ n2 I'M n(n + 1)(2n + 1) 2n' + 3n- + n 6 6