旋转体壳层法演示
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本范例演示通过壳层法计算旋转体体积的过程。涉及的核心数学概念包括定积分、旋转、立体几何体积、二次函数、自然数、三角函数等。作图要点使用了Point、CurveCartesian、Integral、Segment、Line、Surface、Sequence等GeoGebra命令与对象,如yMax, yMin, xMin, xMax, UpperFunction, ShellBar等,通过滑块和动态演示展示体积积分计算。适合高中及以上学生及微积分教学使用。
GeoGebra 命令及参数
Point(y = 0) → RPoint(xAxis) → RightEndPoint(xAxis) → LeftEndCurveCartesian(t, (0.8 * yMin) + (0.2 * yMax), t, x(LeftEnd), x(RightEnd)) → ShellBarPoint(ShellBar) → ShellPointCurveCartesian(t, UpperFunction(t), t, x(LeftEnd), x(RightEnd)) → UpperCurveTextfield(UpperFunction) → UpperFunctionBoxIntegral(ShellArea, x(LeftEnd), x(ShellPoint)) → VolumeToDiskIntegral(ShellArea, x(LeftEnd), x(RightEnd)) → FullVolumeTextfield(xMin) → xMinBoxTextfield(xMax) → xMaxBoxTextfield(yMin) → yMinBoxTextfield(yMax) → yMaxtBoxCurveCartesian(t, LowerFunction(t), t, x(LeftEnd), x(RightEnd)) → LowerCurveSegment((x(ShellPoint), LowerFunction(x(ShellPoint))), (x(ShellPoint), UpperFunction(x(ShellPoint)))) → LineToCurveTextfield(LowerFunction) → LowerFunctionBoxLine(R, R + (0, 1)) → AxisOfRotationSurface(x(R) + (cos(t) * (x(ShellPoint) - x(R))), (s * UpperFunction(x(ShellPoint))) + ((1 - s) * LowerFunction(x(ShellPoint))), (sin(t) * (x(ShellPoint) - x(R))), s, 0, 1, t, 0, 6.28319) → IntegrationDiskSurface(x(R) + (cos(t) * (s - x(R))), UpperFunction(s), (sin(t) * (s - x(R))), s, x(LeftEnd), x(RightEnd), t, 6.2832 - RotationAngleShown, 6.2832) → SurfaceRevSurface(x(R) + (cos(t) * (s - x(R))), LowerFunction(s), (sin(t) * (s - x(R))), s, x(LeftEnd), x(RightEnd), t, 6.2832 - RotationAngleShown, 6.2832) → SurfaceRevInnerSequence(CurveCartesian[x(R) + (cos((((n + 0.5) * 2) * π / 12)) * (t - x(R))), UpperFunction(t), (sin((((n + 0.5) * 2) * π / 12)) * (t - x(R))), t, x(LeftEnd), x(RightEnd)], n, 0, 11) → WireFrameRibsSequence(CurveCartesian[x(R) + (cos((((n + 0.5) * 2) * π / 12)) * (t - x(R))), LowerFunction(t), (sin((((n + 0.5) * 2) * π / 12)) * (t - x(R))), t, x(LeftEnd), x(RightEnd)], n, 0, 11) → WireFrameRibsInner