MAT020 · Matrices & determinants · Class 12
Matrices
A 2 × 2 matrix [[a, b], [c, d]] transforms the plane. Its determinant tells how areas scale.
Matrices📐 Formula
det = ad − bc; the unit square becomes a parallelogram of area |det|
✏️ Worked example
[[2, 1], [0, 1]]: det = 2 → areas double (a shear plus stretch).
🌍 Where it is used
Computer graphics, robotics and solving linear systems.
❓ Quick check
det [[3, 1], [2, 4]] =