定积分演示（I）

GeoGebra 命令及参数

1. Textfield(f) → InputBox1
2. Textfield(a) → InputBox2
3. Textfield(b) → InputBox3
4. Sequence((a + (i * deltax), 0), i, 1, n, 1) → rightx
5. Sequence((a + (i * deltax), f(a + (i * deltax))), i, 1, n, 1) → fofrightx
6. Sequence((a + (i * deltax), 0), i, 0, n - 1, 1) → leftx
7. Sequence(Midpoint[Element[leftx, i], Element[rightx, i]], i, 1, n, 1) → midpoints
8. Sequence((a + (i * deltax), f(a + (i * deltax))), i, 1, n, 1) → list1
9. Translate(list1, (deltax, 0)) → list1'
10. LeftSum(f, a, b, n) → l
11. Sequence(x = x(Element[midpoints, i]), i, 1, n, 1) → list2
12. Sequence(Intersect[f, Element[list2, i], (0, 5.6094379124341005)], i, 1, n, 1) → list3
13. Translate(list3, (deltax / 2, 0)) → midpointtopright
14. Translate(list3, (((-deltax)) / 2, 0)) → midpointtopleft
15. Translate(midpoints, (deltax / 2, 0)) → midpoints'
16. Translate(midpoints, (((-deltax)) / 2, 0)) → midpoints'_1
17. Sequence(Polygon[Element[midpoints'_1, i], Element[midpoints', i], Element[midpointtopright, i], Element[midpointtopleft, i]], i, 1, n, 1) → list4
18. Sum(list4) → h
19. Translate(list1, ((-deltax), 0)) → list1'_1
20. Translate(rightx, ((-deltax), 0)) → rightx'
21. Sequence(Polygon[Element[rightx, i], Element[list1, i], Element[list1'_1, i], Element[rightx', i]], i, 1, n, 1) → rightrectanglesum
22. Sum(rightrectanglesum) → j
23. Intersect(k, p) → F
24. Intersect(m, k) → G
25. Polygon(D, E, G, F) → poly1, d_1, e, g_1, f_1
26. Intersect(m, q) → H
27. Intersect(p, q) → I
28. Polygon(D, E, H, I) → poly2, d_2, e_1, h_1, i_1
29. Intersect(p, r) → J
30. Intersect(r, m) → K
31. Polygon(D, E, K, J) → poly3, d_3, e_2, k_1, j_1
32. Integral(f, a, b) → s