旋转体的表面积

GeoGebra 命令及参数

1. Point(xAxis) → A
2. Point(Ray[A, A + (1, 0)]) → B
3. Textfield(f) → InputBox1
4. Sequence((a + (k * w), f(a + (k * w))), k, 0, n) → L_1
5. PolyLine(L_1) → g
6. Surface(g, (2 * π), y = 0) → surface
7. Rotate(g, θ, xAxis) → g'
8. CurveCartesian(a + ((k - 1 + t) * w), ((1 - t) * f(a + ((k - 1) * w))) + (t * f(a + (k * w))), t, 0, 1) → c
9. Surface(c, (2 * π), y = 0) → d