Suppose f(m) __ 14. (a) The rectangles in the graph on the left illustrate a left endpoint Riemann sum for x) on the interval 4 S m S 6. The value of this left endpoint Riemann sum is D, and it is an the area of the region enclosed by y = x), the xaxis, and the vertical linesa: = 4and a: = 6. (b) The rectangles in the graph on the right illustrate a right endpoint Riemann sum for f(:z:) on the interval 4 S a: S 6. The value of this right endpoint Riemann sum is D, and it is an underestimate of 3 the area of the region enclosed by y = rs), the x-axis, and the vertical linesa: = 4and a: = 6. HMWAU'IUI'NIG HMLUAU'Im'NIm Left endpoint Riemann sum Right endpoint Riemann sum