(a)[1]
Which one of these four matrix calculations cannot be done? $A + B$, $3C$, $CB$, $AD$.
(b)[2]
Calculate the matrix product $AB$.
(c)[2]
Work out $B^{-1}$, the inverse matrix of $B$.
(d)[1]
Explain why matrix $A$ has no inverse.
Mathematics 0580 · IGCSE · Algebraic manipulation
Algebraic manipulation — practice question
The matrices are defined as follows:
$A = \begin{pmatrix}4 & 2 \\ 2 & 1\end{pmatrix}$,
$B = \begin{pmatrix}7 & -3 \\ 4 & 5\end{pmatrix}$,
$C = \begin{pmatrix}-2 & 3 & 1 \\ 4 & 5 & -1\end{pmatrix}$,
$D = \begin{pmatrix}-9 \\ 0\end{pmatrix}$.