Question

Left Riemann's sum problem!

I'm asked to draw a left riemann's sum diagram of cosx on the interval
[-pi/2,pi/2] with 6 boxes. So split the x axis into 7 parts (increments of pi/6) and i found that on the right of zero, the sum overestimates and to the left of zero, the sum underestimates. Also I only got 5 boxes because the height at -pi/2 would be zero. So does the box with zero area count? Or did I do something wrong?

Will the overestimate on the right cancel out with the underestimate on the left?

Answer 1

best to draw us a picture :)

Answer 2

Ok hold on