Determinants.

11 lessons93 min2 simulations

A determinant is a single number computed from a square matrix. For a 2 × 2 matrix it is ad − bc, and it decides at once whether the matching pair of linear equations has exactly one solution. This chapter evaluates determinants of order 1, 2 and 3, uses them for the area of a triangle, builds minors, cofactors and the adjoint, finds A⁻¹ = (1/|A|) adj A, and solves systems AX = B by the matrix method, with a test for when a system has no solution.

Also called: determinant · Cramer's rule · adjoint and inverse