旋转体体积-圆环法
几何画板及绘图内容加载中,请稍等……
本示例演示了2011年AP考试第3c题中的旋转体体积计算。涉及的核心数学概念包括积分和旋转体体积。通过使用GeoGebra中的Sequence, Polygon, Rotate, Integral等命令,可以构造出旋转体的横截面,并通过积分计算其体积。适合高中微积分课程使用。
GeoGebra 命令及参数
Sequence(Polygon[((k * h), f(((k + p) * h))), (((k + 1) * h), f(((k + p) * h))), (((k + 1) * h), g(((k + p) * h))), ((k * h), g(((k + p) * h)))], k, 0, m - 1) → RectanglesPolygon(((DK * h), f(((DK + p) * h))), (((DK + 1) * h), f(((DK + p) * h))), (((DK + 1) * h), g(((DK + p) * h))), ((DK * h), g(((DK + p) * h)))) → Rectangle1, b, c, d, eRotate(Rectangle1, α, a) → Rectangle1'Integral((π * ((1 - f(x))^(2) - (1 - g(x))^(2))), 0, 1 / 2) → VolIntegRotate(Rectangles, α, a) → Rectangles'Rotate(g_1, α, a) → iRotate(f_1, α, a) → jSurface(u, 1 - ((1 - f(((DK + p) * h))) * cos(β)), ((1 - f(((DK + p) * h))) * sin(β)), u, (DK * h), ((DK + 1) * h), β, 0, α) → Inner1Surface(u, 1 - ((1 - g(((DK + p) * h))) * cos(β)), ((1 - g(((DK + p) * h))) * sin(β)), u, (DK * h), ((DK + 1) * h), β, 0, α) → Outer1Surface((DK * h), 1 - ((1 - u) * cos(β)), ((1 - u) * sin(β)), u, f(((DK + p) * h)), g(((DK + p) * h)), β, 0, α) → SideLeft1Surface(((DK + 1) * h), 1 - ((1 - u) * cos(β)), ((1 - u) * sin(β)), u, f(((DK + p) * h)), g(((DK + p) * h)), β, 0, α) → SideRight1Surface(u, 1 + ((1 - g(u)) * cos(β)), ((1 - g(u)) * sin(β)), u, 0, 1 / 2, β, 0, (2 * π)) → InnerSurface(u, 1 - ((1 - f(u)) * cos(β)), ((1 - f(u)) * sin(β)), u, 0, 1 / 2, β, 0, (2 * π)) → OuterSequence(Surface[u, 1 - ((1 - g(((k + p) * h))) * cos(β)), ((1 - g(((k + p) * h))) * sin(β)), u, (k * h), ((k + 1) * h), β, 0, α], k, 0, m - 1) → InnersSequence(Surface[u, 1 - ((1 - f(((k + p) * h))) * cos(β)), ((1 - f(((k + p) * h))) * sin(β)), u, (k * h), ((k + 1) * h), β, 0, α], k, 0, m - 1) → OutersSequence(Surface[(k * h), 1 - ((1 - u) * cos(β)), ((1 - u) * sin(β)), u, f(((k + p) * h)), g(((k + p) * h)), β, 0, α], k, 0, m - 1) → SidesLeftSequence(Surface[((k + 1) * h), 1 - ((1 - u) * cos(β)), ((1 - u) * sin(β)), u, f(((k + p) * h)), g(((k + p) * h)), β, 0, α], k, 0, m - 1) → SidesRightRectangleSum(A, 0, (m * h), m, p) → WS