Determinant Command Determinant( <Matrix> ) Gives the determinant of the matrix. Determinant({{1, 2}, {3, 4}}) yields a = -2. CAS Syntax Determinant( <Matrix> ) Gives the determinant of the matrix. If the matrix contains undefined variables, it yields a formula for the determinant. Determinant({{1, a}, {b, 4}}) yields -a b + 4.