Tangent of Hyperbola and Light Reflection

Tangent of Hyperbola and Light Reflection
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2017-07-18 12:44
In collections Conic sections
① This example demonstrates the tangent line at a point on a hyperbola and the path of light rays reflecting off that tangent, illustrating the optical property of a hyperbola. ② Core mathematical concepts include the definition of a hyperbola, tangent equations, focal properties, and the law of reflection (angle of incidence equals angle of reflection), bridging analytic geometry and geometric optics. ③ Construction details: using GeoGebra commands such as Hyperbola to create the curve, Point for a moving point, Vector for direction vectors, Intersect for intersection points, If for conditional logic, and Line for drawing the tangent and reflected rays; objects include foci F, F_1, F_2, tangent line t, moving point A, vector v, and numerous auxiliary lines (b, c, e, i, l, m, etc.) to build the reflection path and interactive button. ④ Suitable for high school or college analytic geometry courses to understand conic optical properties, and for physics demonstrations of reflection laws; ideal for classroom interaction or self-directed exploration.

GeoGebra Commands & Parameters

  1. Hyperbola(F_1, F_2, F) → d
  2. Point(d) → B
  3. Vector(F_1, B) → v
  4. Intersect(d, xAxis, 1) → A
  5. Vector(F_2, B) → u
  6. If(t ≤ 1, ((t * x(u)) + x(F_2), (t * y(u)) + y(F_2))) → D
  7. If(t ≟ 2, Tangent[B, d]) → f
  8. Point(f) → G
  9. If(t ≥ 1, (((t - 1) * x(v)) + x(B), ((t - 1) * y(v)) + y(B))) → C
  10. Line(F_1, B) → h
  11. If(t ≤ 1, Vector[F_2, D]) → u_{53}
  12. Vector(B, C) → v_{53}
  13. If(t ≥ 1, Segment[F_2, B]) → g
  14. If(t ≥ 2, Line[F_1, B]) → p_{53}

AI Drawing Prompt Reference

Draw a hyperbola defined by two foci and a third point, with a moving point on it. From this moving point, draw vectors to both foci, and extend a ray from the moving point along the direction of one focus. At the intersection of the hyperbola with the horizontal axis, construct a tangent line that changes as the moving point moves. Pick a point on the tangent, draw a line from the other focus to this point, and construct the reflected light path from this point along the tangent direction. Connect the foci and the moving point with segments, and make some segments and vectors appear or disappear with a parameter to demonstrate the optical property that light reflects off the tangent and passes through the other focus.
The prompt above was compiled from the original drawing commands and is for reference only.