Estimate the area under the graph of

Question

f(x)=sin(pix) from x=0 to x=1 using the areas of 3 rectangles of equal width, with heights of the rectangles determined by the height of the curve at

a) left endpoint:
b) right endpoint:

Answer 1

what's the trouble?

You have 3 rectangles, each of width 1/3
Using left endpoints, the heights are
0,√3/2,√3/2
add up the rectangle areas.

Similarly, using right endpoints.

Answer 2

I tried that, and it was incorrect