Matrix Determinant + Inverse (2×2 / 3×3)

Determinant and inverse for 2×2 or 3×3 matrices. Inverse exists iff det ≠ 0.

Inputs

Result

Determinant
10.0000
Inverse: [[0.6000, -0.7000], [-0.2000, 0.4000]]
  • Matrix[[4, 7], [2, 6]]
  • det = ae − bd10.000000
  • Inverse [0,0] = e/det0.600000
  • Inverse [0,1] = −b/det-0.700000
  • Inverse [1,0] = −d/det-0.200000
  • Inverse [1,1] = a/det0.400000

Step-by-step

  1. 2×2 det = ae − bd = 4·6 − 7·2 = 10.0000.
  2. 2×2 inverse = (1/det) · [[e, −b], [−d, a]] (swap diagonal, negate off-diagonal, divide by det).

How to use this calculator

  • Pick 2×2 or 3×3 from the dropdown.
  • Enter entries row-by-row. For 2×2, only a/b/d/e matter.
  • Read the determinant; the inverse appears below if det ≠ 0.

About this calculator

Two operations central to linear algebra. The determinant det(M) is a scalar that measures volume scaling under the linear transformation M (and orientation: negative det = reflection). For a square matrix M, the inverse M⁻¹ exists if and only if det(M) ≠ 0 (the matrix is non-singular). 2×2 inverse: swap diagonal entries, negate off-diagonal, divide by det. 3×3 inverse via the adjugate (= transpose of the cofactor matrix) divided by the determinant: M⁻¹ = adj(M)/det. For larger matrices the formula extends but is computationally expensive; Gaussian elimination is preferred from 4×4 upward. Singular matrices arise when rows (or columns) are linearly dependent — geometrically, the transformation collapses the space onto a lower-dimensional subspace.

Frequently asked

The matrix collapses space: rows are linearly dependent, so the transformation has a non-trivial null space. A 2×2 with det=0 maps the plane onto a line; a 3×3 with det=0 maps 3-space onto a plane or line.

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