Type any 3×3 matrix and watch it smoothly warp space: the unit cube becomes a parallelepiped whose volume is the determinant, and real eigenvectors light up as the lines that only stretch. Computes the determinant, inverse, rank, trace, eigenvalues, singular values and condition number.
A 3×3 matrix is a machine that moves every point of space: v ↦ A v. Its three columns are exactly where the basis vectors x̂ (red), ŷ (green) and ẑ (blue) land, and every other point follows because the map is linear — grid lines stay straight, parallel and evenly spaced, and the origin never moves.
A v = λ v. The eigenvalues are the roots of the characteristic cubic λ³ − tr(A) λ² + c₂ λ − det(A) = 0, solved here in closed form (complex pairs mean a rotation part).A⁻¹ = adj(A) / det(A).(1−t) I + t A, a straight-line blend from “do nothing” to A. It is a visual aid, not a path through rotations.Worked example: the shear [[1,1,0],[0,1,0],[0,0,1]] tilts the cube but keeps its volume (det = 1); its only eigen-direction is x̂, with λ = 1 repeated three times.