Original revision introduction and starter practice. Full learning texts are available through the publisher links below. This guide is not a CBSE-issued solution manual.
Revision introduction
A matrix is an ordered rectangular array. Addition requires equal dimensions; AB requires columns of A to equal rows of B. Matrix multiplication is generally not commutative. A square matrix with non-zero determinant is invertible. Check a computed inverse by multiplying to obtain the identity.
Curriculum navigation
Relations and Functions
Inverse Trigonometric Functions
Matrices
Determinants
Continuity and Differentiability
Application of Derivatives
Integrals
Application of Integrals
Differential Equations
Vectors
Three-dimensional Geometry
Linear Programming
Probability
Consult the current official syllabus for examinable sections, project-only content, practicals, prescribed texts and exclusions. A unit index does not override those boundaries.
Original practice
When is a square matrix invertible?
Its determinant is non-zero
Its determinant is zero
It has any zero entry
It has unequal row and column counts
Worked answer
Its determinant is non-zero
A non-zero determinant is the condition for invertibility of a square matrix.
Full publisher materials and answer resources
CBSE 12 Mathematics · syllabus · CBSE · 2026-27 The current official syllabus defines examinable content, internal assessment, practicals and prescribed books. Unit names in the app are a navigation index; consult this document for exclusions and assessment boundaries.
NCERT textbook portal · Mathematics · NCERT · 2026-27 Select Class 12, subject and prescribed book. Book selectors change as editions are released.
NCERT Exemplar Problems and Answers · NCERT · Archive · map to 2026-27 Select Class 12 and the subject. The official portal includes answer sections. Older exemplars require checking each question against the current syllabus.
KVS student support material · Class 12 · Kendriya Vidyalaya Sangathan · 2026-27 Use the 2026–27 support-material folders linked by the school. These are KVS teaching/revision resources, not CBSE official marking schemes. Subject availability varies; older packs must be mapped to the current syllabus.
CBSE 2026–27 · Sample question paper · CBSE · 2026-27 Official document listed by CBSE for 2026–27. Open at the publisher; no third-party solutions are represented as official. Sample papers are practice models, not previous board examination papers.
CBSE 2026–27 · Official marking scheme / answer key · CBSE · 2026-27 Official document listed by CBSE for 2026–27. Open at the publisher; no third-party solutions are represented as official. Sample papers are practice models, not previous board examination papers.
DIKSHA · curriculum learning resources · Ministry of Education / DIKSHA · Current portal Choose CBSE/NCERT, Class 12, subject and medium. This is a searchable portal, not a promise of a specific playable lesson.