In this question, you will estimate the area under the curve y = 3x2 from x = 2 to x = 4 using three different Riemann sums. You will subdivide the interval [2,4] into four sub-intervals of equal width. a. Using our standard notation for Riemann sums, enter the values of a, b, n, and Ax. a = b = n = AX = b. Complete the following table listing the four sub-intervals: First subinterval Second subinterval : [ Third subinterval : Fourth subinterval : [ c. In the next two parts of the question, you will calculate the approximate area under the curve using the left end-points of the sub-intervals. Complete the following table X1 : f ( x 1 ) : X2 : f ( x2 ) : X3: f ( x3 ) : X4 f ( x4 )