Shell Method for Solids of Revolution
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This example demonstrates the calculation of solid of revolution volume using the shell method. It involves core math concepts like definite integral, rotation, solid geometry volume, quadratic functions, natural numbers, trigonometry, etc. Construction highlights the use of GeoGebra commands/objects such as Point, CurveCartesian, Integral, Segment, Line, Surface, Sequence, with elements like yMax, yMin, xMin, xMax, UpperFunction, ShellBar, etc., to dynamically visualize volume integration. Suitable for high school and above students, and calculus education purposes.
GeoGebra Commands & Parameters
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