Maths- finding matrix representing transformation(IGCSE)

[ForeignHorse]

For question (b), how do you find the matrix?

Normally they will give you the matrix and find the transformation instead of finding the matrix right?

Are there any specific formula for this ?

Thanks.

Edited May 5, 2014 by ForeignHorse

[Orodruin]

The matrix is directly related to the transformation. I suggest you think along the following lines:

1. I want to map A to B, what does this mean? Which points in A should be mapped to which points in B?
2. How can I write down the conditions describing that a certain point in A maps to a certain point in B?
3. How can I use this information to deduce the elements of the transformation matrix?

A different way would be to think along the lines:

1. How are the x and y values of the points and the transformed points related?
2. How can I describe this with a matrix equation?