When asked to describe a transformation fully, the mark scheme expects ALL parameters:
| Transformation | Parameters required |
|---|
| Translation | Vector (ab) |
| Reflection | Equation of mirror line |
| Rotation | Centre, angle, direction |
| Enlargement | Centre, scale factor |
Worked. Triangle A with vertices (2,1),(4,1),(4,3) maps to A′ at (−1,−2),(1,−2),(1,0). Describe the transformation.
- Differences: (2→−1)=−3, (1→−2)=−3. Same shift on both coordinates.
- Translation by (−3−3).
Step-by-step approach to identifying transformations.
- Same orientation, same size? Try TRANSLATION.
- Same size, mirror image? Try REFLECTION.
- Same size, rotated? Try ROTATION (find centre).
- Different size? Try ENLARGEMENT.
Tip. Check at least TWO points to be sure of the transformation. One point is consistent with many transformations.