Systems of Linear Equations (AQA A-Level Further Maths): Flashcards

$ad - bc$

Matrix with $\det(A) = 0$

No inverse exists

$\det(A) \times \det(B)$

$\begin{pmatrix} 1 & 0 \\ 0 & 1 \end{pmatrix}$

$AA^{-1} = A^{-1}A = I$

$\frac{1}{\det(A)} \begin{pmatrix} d & -b \\ -c & a \end{pmatrix}$

$\frac{1}{\det(A)}$

$\pm 1$ (either +1 or -1)

$\mathbf{x} = M^{-1}\mathbf{b}$