Inverse Matrices and Solving Simultaneous Equations Using Matrices (VCE SSCE General Mathematics): Flashcards

Matrix that when multiplied by original gives identity matrix

$A \times A^{-1} = I = A^{-1} \times A$

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

Only square matrices (same rows and columns)

$ad - bc$

When its determinant equals zero

$A \times X = C$

Variables matrix containing the unknowns

$X = A^{-1} \times C$

Not commutative; order matters