Ruled

Module 1

Matrices

From notation to eigenvalues. Every named type of matrix, every standard operation, and every method the exam asks for — worked in full.

9 topics · 88 solved problems

Module contents
  1. 01

    Matrices, order and notation

    What a matrix is, how its order is written, how to name an element, and when two matrices count as equal.

    3 worked · 5 practice
  2. 02

    Types of matrices

    Every named matrix in the syllabus — row, column, null, diagonal, scalar, identity, triangular, symmetric, skew-symmetric, orthogonal, idempotent, involutory, nilpotent, periodic, Hermitian, unitary and more — each with its defining test and a solved check.

    5 worked · 8 practice
  3. 03

    Matrix operations

    Addition, subtraction, scalar multiplication and the row-by-column product — with the conformability rules, the algebraic laws that survive and the ones that fail.

    4 worked · 6 practice
  4. 04

    Determinants

    Evaluating 2×2 and 3×3 determinants, cofactor expansion along any row or column, Sarrus' rule, and the seven properties that turn a hard determinant into an easy one.

    4 worked · 7 practice
  5. 05

    Adjoint and inverse

    Building the cofactor matrix, transposing it to get the adjoint, and dividing by the determinant to get the inverse — plus the Gauss–Jordan route and the properties of A⁻¹.

    3 worked · 7 practice
  6. 06

    Elementary operations, echelon form and rank

    Row-reducing a matrix to echelon form, reading the rank off the staircase, and the minor method as a cross-check.

    3 worked · 6 practice
  7. 07

    Systems of linear equations

    Matrix form AX = B, the consistency test by rank, and four solution methods — Cramer's rule, the inverse method, Gauss elimination and Gauss–Jordan — including homogeneous systems.

    5 worked · 7 practice
  8. 08

    Eigenvalues and eigenvectors

    The characteristic equation, finding eigenvalues for 2×2 and 3×3 matrices, extracting eigenvectors, and the properties that let you check an answer in seconds.

    3 worked · 6 practice
  9. 09

    Cayley–Hamilton theorem

    Every matrix satisfies its own characteristic equation — and how to use that to find inverses and reduce high powers without heavy computation.

    2 worked · 4 practice

Syllabus coverage

  • Definition, order, types of matrices
  • Addition, scalar multiplication and multiplication of matrices
  • Transpose, symmetric and skew-symmetric matrices
  • Determinants and their properties
  • Minors, cofactors, adjoint and inverse
  • Elementary transformations, echelon form and rank
  • Solution of linear equations — Cramer's rule, matrix method, Gauss elimination
  • Eigenvalues, eigenvectors and the Cayley–Hamilton theorem