1. Functions and Transformations
In standard algebra, a function takes a single number as an input and outputs a new number: f(x) = y.
In Linear Algebra, we scale this concept up. A Transformation (often denoted as T) is a mathematical rule that takes an entire Vector as an input and assigns it to a new Vector output. We write this as T(x) = b.
You can think of a transformation as a machine that takes a point in space, moves it according to specific rules, and drops it in a new location.
2. Matrix Transformations
The magic of linear algebra is that every linear transformation can be perfectly represented by a Matrix. By multiplying a coordinate vector by a transformation matrix, we can scale, rotate, reflect, and shear objects in space.
Try the interactive visualizer below. Watch how changing the values in the 2×2 Matrix (A) physically alters the “F” shape on the 2D Cartesian plane.
3. Properties of Matrix Transformations
For a transformation to be considered a mathematically valid Linear Transformation, it must rigidly follow two specific properties. If a matrix represents the transformation, these properties are automatically guaranteed.
Property 1: Additivity (Superposition)
Transforming two vectors added together yields the exact same result as transforming them individually and then adding their results.
Property 2: Homogeneity (Scalar Multiplication)
Scaling a vector by a constant (c) and then transforming it is the same as transforming the vector first and then scaling the result.
References
- Anton, H., & Rorres, C. Elementary Linear Algebra, 11th Edition (pp. 75-83). Wiley.