What are transformations in maths?
There are 4 transformations in GCSE Maths – rotation, reflection, translation and enlargement
All 4 change a shape in some way, useful in things like computer graphics.
There is some language and notation often used in this topic – the original shape is called the object and the transformed shape is called the image
Vertices are labelled to show corresponding points
Vertices on the object are labelled A, B, C, etc.
Vertices on the image are labelled A’, B’, C’ etc.
If there is a second transformation then they will become A”, B”, C” etc.
What is a translation?
A translation is the movement of a shape
The size, shape and orientation (which way up it is) of the shape stays the same
A real life use of this is
An excellent real-life example of translation is the movement of an aircraft as it moves over the skies. Moving a tangram on a flat surface is also a translation.
this kind of use vectors
Reflections
What is a reflection?
A reflection is a mirror image of an object across a line of reflection/mirror line
The reflected image is the same shape and size as the original object but it has been "flipped" across the mirror line to a new position and orientation
Points on the mirror line do not move, they stay where they are!
How do I reflect a shape?
You need to be able to perform a reflection (on a coordinate grid)
The perpendicular distance between a point on the original object and the mirror line, should be the same as the perpendicular distance between the corresponding point on the reflected image and the mirror line
very easy way to learn this thin the line as the mirror and then flip and paste it on the other side like looking at a mirror
How do I describe a reflection?
You will need to be able to identify and describe a reflection when presented with one
You must fully describe a transformation to get full marks
For a reflection, you must:
State that the transformation is a reflection
Give the mathematical equation of the mirror line
Now the vector i told is basically the math formula so it is easy
Rotations
What is a rotation?
A rotation is the movement of an object around a point
The rotated image is the same size and shape as the original image, but it will have a new position and orientation
now this is too easy first take a paper then draw a shape then you choose a point. then take a pencil and push on the paper on the point and rotate the paper by what ever angle using an protractor .
and in exam, you have to say which direction by saying anti-clockwise or clockwise
Enlargements
What is an enlargement?
An enlargement is a transformation that changes the size of the shape
The scale factor tells you how many times bigger each edge of the enlarged image will be compared to the corresponding edge on the original object
If the scale factor is greater than 1, the enlarged image will be bigger than the original object
If the scale factor is less than 1, the enlarged image will be smaller than the original object
The position of a shape will also change with enlargement
The orientation of the shape will be the same for a positive enlargement
this is size but still there will be points to draw it from but no vectors for this one
What do you mean by Corresponding Points? (Please add a Picture)