A Parabola from Focus and Directrix
Build the equal-distance construction, predict the locus, and generate the curve point by point.
Edexcel IAL Further Mathematics
Coordinate
Geometry
Short, teacher-controlled instruments for the moment when a board diagram needs motion. Predict first, construct in stages, then return to the algebra.
08 ready
00 queued
3–6 min each
Instrument catalogue
A Parameter Draws a Curve
Separate the geometric curve from its parameter, range, and direction of travel.
Secant to Tangent
Watch a secant line settle into the tangent while its gradient stabilises.
Two Foci, Two Conics
Compare the fixed-sum ellipse with the fixed-difference hyperbola.
Reading the Standard Form
Connect parameters with vertices, foci, directrices, and asymptotes.
Curve-Language Challenge
Match a construction, equation, parametrisation, and graph.
Eccentricity and Distance Invariants
Move P between paired directrices and use PF = e·PD to prove the ellipse sum and hyperbola difference.
Conic Sections and Dandelin Spheres
Rotate a depth-lit cone, switch viewpoints, and reveal how tangent spheres locate the foci.