线积分：功

GeoGebra 命令及参数

1. SelectedIndex(pathNames) → pathIndex
2. Midpoint(N, P) → Q
3. Element(pathList, pathIndex) → path
4. Derivative(path) → DDpath
5. ParametricDerivative(path) → Dpath
6. Distance(N, P) → NP
7. Element(CompX, pathIndex) → RTX
8. Derivative(RTX, x) → DRTX
9. Element(CompY, pathIndex) → RTY
10. Derivative(RTY, x) → DRTY
11. CurveCartesian(x(path(t)), y(path(t)), t, 0, s) → partPath
12. Integral(MUL, 0, 1) → Work
13. Textfield(F_1) → InputBox1
14. Textfield(F_2) → InputBox2
15. Segment(path(0.3), path(0.3 + 0.01)) → arrow1
16. Segment(path(0.6), path(0.6 + 0.01)) → arrow2
17. If(Work ≟ Work, Work, Sum[Sequence[((path(i + dS) - path(i)) * (F_1(x(path(i + dS / 2)), y(path(i + dS / 2))), F_2(x(path(i + dS / 2)), y(path(i + dS / 2))))), i, 0, s - dS, dS]]) → WOORK
18. Sequence(Vector[path(i), path(i) + ((scale * F_1(x(path(i)), y(path(i)))), (scale * F_2(x(path(i)), y(path(i)))))], i, 0, s, 0.15) → PathVectors, {(0.10000000000000009, -0.10000000000000009), (0.06999999999999995, -0.06999999999999995), (0.03999999999999998, -0.03999999999999998), (0.010000000000000009, -0.010000000000000009), (-0.01999999999999999, 0.01999999999999999), (-0.050000000000000044, 0.050000000000000044), (-0.08000000000000007, 0.08000000000000007)}
19. Sequence(path(i), i, 0.25, 0.75, 0.25) → PtPathList, {(0.5, -0.5), (0, 0), (-0.5, 0.5)}
20. Sequence(Vector[(0, 0), (1 / sqrt((y(DDpath(i)))^(2) + (x(DDpath(i)))^(2)) * (x(DDpath(i)), y(DDpath(i))))], i, 0.25, 0.75, 0.25) → tangvectorsList, {(-0.7071067811865475, 0.7071067811865475), (-0.7071067811865475, 0.7071067811865475), (-0.7071067811865475, 0.7071067811865475)}
21. Translate(Vector[Element[tangvectorsList, 1]], Element[PtPathList, 1]) → uu
22. Translate(Vector[Element[tangvectorsList, 2]], Element[PtPathList, 2]) → vv
23. Translate(Vector[Element[tangvectorsList, 3]], Element[PtPathList, 3]) → ww
24. Textfield(xA) → InputBox3
25. Textfield(yA) → InputBox4
26. Textfield(xB) → InputBox5
27. Textfield(yB) → InputBox6