Linear Algebra
Study of vectors, matrices, and linear transformations.
Basic Concepts
Matrices and Matrix Operations
Understanding Matrices
A matrix is a neat way to organize numbers into rows and columns, like a spreadsheet in math. We usually write a matrix as a big rectangle: \[ A = \begin{bmatrix} 1 & 2 \ 3 & 4 \end{bmatrix} \]
Matrix Operations
- Addition: Add two matrices by adding their matching entries.
- Scalar multiplication: Multiply each entry by a number.
- Matrix multiplication: Multiply rows by columns. It's a bit tricky but super useful!
Why Matrices Matter
Matrices help us solve systems of equations, rotate shapes, and even encrypt messages!
Example Calculations
- \( \begin{bmatrix}1 & 2\3 & 4\end{bmatrix} + \begin{bmatrix}5 & 6\7 & 8\end{bmatrix} = \begin{bmatrix}6 & 8\10 & 12\end{bmatrix} \)
- Multiplying a matrix by 2 doubles every entry.
Matrix Multiplication
When you multiply matrices, the rows of the first matrix combine with the columns of the second. This lets you do cool things like rotating a picture or transforming data.
Examples
Adding two 2x2 matrices entrywise.
Multiplying a matrix by a scalar to scale all its values.
In a Nutshell
Matrices organize numbers and let us perform operations like addition and multiplication.