Congruency, Enlargement and Combined Transformations
Object and image
The original shape (object) and its result after a transformation (image).
| English | Object and image |
|---|---|
| Bahasa Melayu | Objek dan imej |
| 中文 | 原象与象 |
How it is used
Under a reflection in the y-axis, the object point P(3, 4) has image P′(−3, 4). Here P is the object and P′ is the image, and both lie the same distance from the axis.
Where it shows up in SPM
Basic vocabulary used throughout this Form 5 transformations chapter. Every Paper 2 transformation question names the object and its image, often using primes such as A and A′.
Combined transformation questions track the object through an intermediate image to a final image.
Don't confuse it with
Open the chapter: Congruency, Enlargement and Combined Transformations →
Frequently asked questions
What does the prime symbol A′ mean?
The prime marks the image of a point after a transformation. So A is the object point and A′ is where it lands.
In combined transformations you may see A″ for the image after a second transformation.
In an enlargement, are the object and image congruent?
Only when the scale factor is 1 or −1. For any other scale factor the image is a different size, so the object and image are similar but not congruent.
Under rotation, reflection and translation they are always congruent.