Suppose f(:L') = g. (a) The rectangles in the graph on the left illustrate a left endpoint Riemann sum for at) on the interval 4 g a: S 6. The value of this left endpoint Riemann sum is , and it is an the area of the region enclosed by y = an), the xaxis, and the vertical lines a: = 4 and m = 6. (b) The rectangles in the graph on the right illustrate a right endpoint Riemann sum for at) on the interval 4 S :L' S 6. The value of this right endpoint Riemann sum is , and it is an the area of the region enclosed by y = at), the xaxis, and the vertical lines a: = 4 and a: = 6. s a 7 7 a a 5 5 4 4 3 3 2 2 1 1 Left endpoint Riemann sum Right endpoint Riemann sum