Coordinate brief
Model contract: origin O(0,0) is the fictional visitor hub; 1 coordinate unit = 10 m.
| Site | Coordinate | Quadrant or axis |
|---|---|---|
| Gate G | (−10,−6) | |
| Habitat H | (−6,5) | |
| Wetland W | (4,8) | |
| Clinic C | (8,−4) | |
| Hub O | (0,0) | |
| Rest area R₁ | (−2,7) | |
| Rest area R₂ | (6,2) |
Construct
Draw axes from −12 to 12, label scale and units, then plot all seven sites.
Peer check: cover the table. Ask a partner to recover H and C from your model.
Distance and route evidence
Use d = √[(x₂−x₁)²+(y₂−y₁)²]. Keep exact values until the final step; then round to one decimal place and convert using 1 unit = 10 m.
| Route | Δx | Δy | Substitution | Distance (m) |
|---|---|---|---|---|
| O→W | ||||
| O→C | ||||
| O→H | ||||
| O→R₂ | ||||
| R₂→W |
The shortest route is not automatically the selected route because:
Transformation test
Original rectangle: A(−4,1), B(0,1), C(0,4), D(−4,4).
| Move | A′ | B′ | C′ | D′ | Invariant check |
|---|---|---|---|---|---|
| Translate by (3,−5) | |||||
| Reflect in y-axis | |||||
| Rotate 90° anticlockwise about origin |
Falsify one result
Choose one transformed footprint. Check every vertex using the stated rule, then verify one invariant such as side length, angle or area.
Mathematics can show the new location and shape, but it cannot decide real-world suitability because:
Linear models and limits
Let t be hours after 9:00 am. Let V be the modelled number of visitors passing a fictional checkpoint during that hour.
| t | 0 | 1 | 2 | 3 | 4 |
|---|---|---|---|---|---|
| Model A: V | 40 | 75 | 110 | 145 | 180 |
Constant difference: ________ Equation: ____________________ Gradient meaning: ______________________________
Model B: V=25t+70. Find when both models give the same prediction.
Graph and limitation
A prediction from this model becomes unreliable when:
Constraint decision
Hard constraints: area ≥1,000 m²; perimeter ≤150 m; centre route <110 m; barrier cost ≤$90,000 at $600 per metre in this fictional scenario.
| Option | Dimensions | Centre route |
|---|---|---|
| A | Rectangle 40 m × 30 m | 80 m |
| B | Rectangle 50 m × 22 m | 95 m |
| C | Parallelogram: base 45 m, perpendicular height 25 m, side 28 m | 105 m |
| D | Rectangle 60 m × 18 m | 100 m |
| E | Rectangle 35 m × 30 m | 115 m |
| Option | Area | Perimeter | Cost | All constraints pass? |
|---|---|---|---|---|
| A | ||||
| B | ||||
| C | ||||
| D | ||||
| E |
Reject before you prefer: which options fail, and on which constraint? ______________________________________________________
My declared preference after feasibility: __________________________________________
Recommended option and mathematical reason:
Trade-off or missing evidence:
Auditable expansion proposal
Recommendation
Evidence checklist
| ☐ Labelled coordinate model with scale and units | ☐ Two checked distance calculations |
| ☐ One transformation with invariant check | ☐ Linear model with gradient and intercept interpreted |
| ☐ Constraint matrix and declared preference | ☐ One assumption and one limitation |
Calculation audit trail
Claim → evidence → reasoning
Peer auditor: reproduce one calculation without asking the author. Calculation checked: __________________ Result agrees? Yes / Repair needed
Limitation: