苹果形状的参数曲线与曲面
几何画板及绘图内容加载中,请稍等……
①这个范例通过参数方程演示了如何绘制一个苹果形状的曲线和曲面;②涉及的核心数学概念包括参数曲线、曲面、正交线、交点、镜像、圆弧、距离、角度等;③作图要点使用了GeoGebra命令如CurveCartesian, Tangent, OrthogonalLine, Intersect, Mirror, CircleArc, Distance, Angle, Surface等;④适合高中及以上学生学习和理解参数方程在几何绘图中的应用。
GeoGebra 命令及参数
CurveCartesian((-(p_1 + (3.8 * cos(v)))), (((cos(v) + sin(v) - 1) * (1 + sin(v))) * log(1 - (π * v / 10))) + (p_2 * sin(v)), v, b_1, b_2) → c_3Tangent(B, c_3) → tgOrthogonalLine(B, tg) → lotIntersect(lot, yAxis) → CMirror(B, yAxis) → B'CircleArc(C, B', B) → cDistance(C, B) → rAngle(lot, yAxis) → wiSurface(((r * cos(u)) * sin(v)), ((r * sin(u)) * sin(v)), z(M) - (r * cos(v)), u, π, π + a, v, π, (2 * π) - wi) → eCurveCartesian((r * sin(v)), ((r * 0) * sin(v)), z(M) - (r * cos(v)), v, π, (2 * π) - wi) → k_1CurveCartesian(((r * (-1)) * sin(v)), ((r * 0) * sin(v)), z(M) - (r * cos(v)), v, π, (2 * π) - wi) → k_2Surface((cos(u) * (p_1 + (3.8 * cos(v)))), (sin(u) * (p_1 + (3.8 * cos(v)))), (((cos(v) + sin(v) - 1) * (1 + sin(v))) * log(1 - (π * v / 10))) + (p_2 * sin(v)), u, 0, a, v, b_1, b_2) → appleCurveCartesian((-(p_1 + (3.8 * cos(v)))), (0 * (p_1 + (3.8 * cos(v)))), (((cos(v) + sin(v) - 1) * (1 + sin(v))) * log(1 - (π * v / 10))) + (p_2 * sin(v)), v, b_1, b_2) → c_1CurveCartesian(p_1 + (3.8 * cos(v)), (0 * (p_1 + (3.8 * cos(v)))), (((cos(v) + sin(v) - 1) * (1 + sin(v))) * log(1 - (π * v / 10))) + (p_2 * sin(v)), v, b_1, b_2) → c_2CurveCartesian(p_1 + (3.8 * cos(v)), (((cos(v) + sin(v) - 1) * (1 + sin(v))) * log(1 - (π * v / 10))) + (p_2 * sin(v)), v, b_1, b_2) → c_4