动画演示几何变换与优化问题 by Tim Brzezinski
几何画板及绘图内容加载中,请稍等……
①本范例通过动画演示三角形与圆的几何变换,结合函数图像分析角度与最值问题;②涉及核心概念:几何变换(缩放、旋转)、解析几何、函数最值、优化问题;③构造要点:使用Line, Point, Circle, Dilate, Segment, Intersect, Polygon等命令创建几何对象,并通过Dilate实现变换,Intersect求交点;④适合高中及以上学生,用于理解几何变换、函数优化及解析几何应用。
GeoGebra 命令及参数
Line(A_1, A') → fLine(A_1, C') → gLine(A_1, B') → hPoint(g) → CPoint(g) → C'_1Point(f) → A'_1Point(f) → APoint(h) → BPoint(h) → B'_1Circle(A'_1, 1) → rCircle(A, 1) → tDilate(A_1, If[0 < a ≤ 1, 1 - a, 0], A) → NDilate(A_1, If[0 < a ≤ 1, 1 - a, 0], A') → OSegment(A_1, N) → bSegment(A_1, O) → i_1Dilate(A_1, If[1 < a ≤ 2, 2 - a, 0], B') → PDilate(A_1, If[1 < a ≤ 2, 2 - a, 0], B) → QSegment(A_1, P) → l_1Segment(A_1, Q) → m_1Dilate(A_1, If[2 < a ≤ 3, 3 - a, 0], C') → HDilate(A_1, If[2 < a ≤ 3, 3 - a, 0], C) → ISegment(A_1, H) → cSegment(A_1, I) → dLine(A', B') → jLine(B, A) → kIntersect(j, k) → DLine(C', B') → lLine(B, C) → mIntersect(l, m) → ELine(C', A') → nLine(A, C) → pIntersect(n, p) → FPolygon(A, C, B) → poly1, b_1, a_1, c_1Polygon(A', B', C') → poly3, c', a', b'Dilate(B, If[5 < a ≤ 6, 6 - a, 0], D) → B'_2Segment(B, B'_2) → iDilate(A', If[5 < a ≤ 6, 6 - a, 0], D) → A''Segment(A', A'') → qDilate(B, If[6 < a ≤ 7, 7 - a, 0], E) → B'_3Dilate(C', If[6 < a ≤ 7, 7 - a, 0], E) → C''Segment(B, B'_3) → sSegment(C', C'') → eDilate(A, If[7 < a ≤ 8, 8 - a, 0], F) → A'_2Dilate(C', If[7 < a ≤ 8, 8 - a, 0], F) → C''_1Segment(C', C''_1) → f_1Segment(A, A'_2) → g_1Dilate(D, If[10 < a ≤ 11, 11 - a, 0], E) → D'Dilate(E, If[11 < a ≤ 12, 12 - a, 0], F) → E'Segment(D, D') → h_1Segment(E, E') → j_1