Question 1031352
Left sum < Trapezoidal rule value < Right sum 

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For the function function f(x) that is positive, increasing and concave down on the closed interval [a, b], 

The left sum (or lower Riemann sum, w/c makes use of the left endpoint of the subinterval) is less than the right sum (or upper Riemann sum, w/c makes use of the right endpoint of the subinterval).  The trapezoidal approximation makes use of both endpoints, but has an area that is the average of the areas of the inscribed and circumscribed rectangles.  (Verify!)