A matrix is a grid of numbers. A matrix with m rows and n columns is called an m×n matrix. Matrices are fundamental to linear algebra, machine learning, and 3D graphics.
Key Operations
- Addition: Add corresponding elements (matrices must be same size)
- Multiplication: Row×column dot products (columns of A must equal rows of B)
- Determinant: Scalar value that indicates invertibility (det ≠ 0 means invertible)
- Transpose: Swap rows and columns (A^T)
2×2 Determinant
For matrix [[a,b],[c,d]]: det = ad − bc