积分体积演示
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①本范例演示通过积分计算旋转体的体积,以X轴为旋转轴的曲线旋转形成的立体图形;②涉及的核心数学概念包括积分、旋转体体积、函数图像、极限等;③作图要点——从下方『构造摘要』提炼用到了哪些 GeoGebra 命令/对象:Textfield, Integral, Sequence, Sum, Surface, CircumcircleSector, f, upperlimit, lowerlimit, number, b, a, inputBox1, inputBox2, inputBox3, AreabyDefiniteIntegral, LeftRectanglesEstimate, RightRectanglesEstimate, VerticalLinesWithinLimits, PointsOnCurvefWithinLimits, h, θ, fprime, CurvedBoundary, LLDisc, ULDisc, LeftRectangleRotate, LeftCylinderLeftSector, LeftCylinderRightSector, LeftCylinderCurvedSurface, RightCylinderEstimate, RightCylinderLeftSector, RightCylinderRightSector, RightRectangleRotate, VolumeRightCylinderEstimate, LeftCylinderEstimate, VolumeLeftCylinderEstimate;④适合高中及以上学生学习微积分和立体几何,用于理解积分在体积计算中的应用。
GeoGebra 命令及参数
Textfield(f) → inputBox1Textfield(upperlimit) → inputBox2Textfield(lowerlimit) → inputBox3Integral(f, ll, ul) → AreabyDefiniteIntegralSequence(Polygon[(dx, 0), (dx, f(dx)), (dx + (ul - ll) / number, f(dx)), (dx + (ul - ll) / number, 0)], dx, ll, ul - (ul - ll) / number, (ul - ll) / number) → LeftRectanglesEstimateSum(LeftRectanglesEstimate) → AreaLeftRectangleEstimateSequence(Polygon[(dx, 0), (dx, f(dx + (ul - ll) / number)), (dx + (ul - ll) / number, f(dx + (ul - ll) / number)), (dx + (ul - ll) / number, 0)], dx, ll, ul - (ul - ll) / number, (ul - ll) / number) → RightRectanglesEstimateSum(RightRectanglesEstimate) → AreaRightRectangleEstimateSequence(x = dx, dx, ll, ul, (ul - ll) / number) → VerticalLinesWithinLimitsSequence((dx, f(dx)), dx, ll, ul, (ul - ll) / number) → PointsOnCurvefWithinLimitsSurface(fprime, θ, xAxis) → CurvedBoundaryCircumcircleSector((ll, f(ll), 0), (ll, (f(ll) * cos(θ / 3)), (f(ll) * sin(θ / 3))), (ll, (f(ll) * cos(θ)), (f(ll) * sin(θ)))) → LLDiscCircumcircleSector((ul, f(ul), 0), (ul, (f(ul) * cos(θ / 3)), (f(ul) * sin(θ / 3))), (ul, (f(ul) * cos(θ)), (f(ul) * sin(θ)))) → ULDiscSequence(Polygon[(dx, 0, 0), (dx, (f(dx) * cos(θ)), (f(dx) * sin(θ))), (dx + (ul - ll) / number, (f(dx) * cos(θ)), (f(dx) * sin(θ))), (dx + (ul - ll) / number, 0, 0)], dx, ll, ul - (ul - ll) / number, (ul - ll) / number) → LeftRectangleRotateSequence(CircumcircleSector[(dx, f(dx), 0), (dx, (f(dx) * cos(θ / 3)), (f(dx) * sin(θ / 3))), (dx, (f(dx) * cos(θ)), (f(dx) * sin(θ)))], dx, ll, ul - (ul - ll) / number, (ul - ll) / number) → LeftCylinderLeftSectorSequence(CircumcircleSector[(dx + (ul - ll) / number, f(dx), 0), (dx + (ul - ll) / number, (f(dx) * cos(θ / 3)), (f(dx) * sin(θ / 3))), (dx + (ul - ll) / number, (f(dx) * cos(θ)), (f(dx) * sin(θ)))], dx, ll, ul - (ul - ll) / number, (ul - ll) / number) → LeftCylinderRightSectorSequence(Surface[u, (f(dx) * cos(v)), (f(dx) * sin(v)), u, dx, dx + (ul - ll) / number, v, 0, θ], dx, ll, ul - (ul - ll) / number, (ul - ll) / number) → LeftCylinderCurvedSurfaceSequence(Cylinder[(dx, 0, 0), (dx + (ul - ll) / number, 0, 0), f(dx + (ul - ll) / number)], dx, ll, ul - (ul - ll) / number, (ul - ll) / number) → RightCylinderEstimateSequence(CircumcircleSector[(dx, f(dx + (ul - ll) / number), 0), (dx, (f(dx + (ul - ll) / number) * cos(θ / 3)), (f(dx + (ul - ll) / number) * sin(θ / 3))), (dx, (f(dx + (ul - ll) / number) * cos(θ)), (f(dx + (ul - ll) / number) * sin(θ)))], dx, ll, ul - (ul - ll) / number, (ul - ll) / number) → RightCylinderLeftSectorSequence(CircumcircleSector[(dx + (ul - ll) / number, f(dx + (ul - ll) / number), 0), (dx + (ul - ll) / number, (f(dx + (ul - ll) / number) * cos(θ / 3)), (f(dx + (ul - ll) / number) * sin(θ / 3))), (dx + (ul - ll) / number, (f(dx + (ul - ll) / number) * cos(θ)), (f(dx + (ul - ll) / number) * sin(θ)))], dx, ll, ul - (ul - ll) / number, (ul - ll) / number) → RightCylinderRightSectorSequence(Polygon[(dx, 0, 0), (dx, (f(dx + (ul - ll) / number) * cos(θ)), (f(dx + (ul - ll) / number) * sin(θ))), (dx + (ul - ll) / number, (f(dx + (ul - ll) / number) * cos(θ)), (f(dx + (ul - ll) / number) * sin(θ))), (dx + (ul - ll) / number, 0, 0)], dx, ll, ul - (ul - ll) / number, (ul - ll) / number) → RightRectangleRotateSum(RightCylinderEstimate) → VolumeRightCylinderEstimateSequence(Cylinder[(dx, 0, 0), (dx + (ul - ll) / number, 0, 0), f(dx)], dx, ll, ul - (ul - ll) / number, (ul - ll) / number) → LeftCylinderEstimateSum(LeftCylinderEstimate) → VolumeLeftCylinderEstimateIntegral(f(x)^(2)) → h_1Sequence(Surface[u, (f(dx + (ul - ll) / number) * cos(v)), (f(dx + (ul - ll) / number) * sin(v)), u, dx, dx + (ul - ll) / number, v, 0, θ], dx, ll, ul - (ul - ll) / number, (ul - ll) / number) → RightCylinderCurvedSurfaceSurface(u, (v * f(u)), 0, u, lowerlimit, upperlimit, v, 0, 1) → Areain3D