Wat is de
omgekeerde
matrix van
  ?
A.  \(\small\boldsymbol{\begin{bmatrix}0&\frac 12\\\frac 12&0\\\end{bmatrix} }\)
B.  \(\small\boldsymbol{\begin{bmatrix}0&-2\\-2&0\\\end{bmatrix} }\)
C.  \(\small\boldsymbol{\begin{bmatrix}0&-\frac 12\\-\frac 12&0\\\end{bmatrix} }\)
D.  \(\small\boldsymbol{\begin{bmatrix}2&0\\0&2\\\end{bmatrix} }\)
E.  \(\text{bestaat niet}\)
A    B    C    D    E

[ 5-0453 - op net sinds 2.3.98-(E)-14.7.2024 ]

Translation in   E N G L I S H

The inverse of
the square matrix

is
A.   \(\small\boldsymbol{\begin{bmatrix}0&\frac 12\\\frac 12&0\\\end{bmatrix} }\)
B.   \(\small\boldsymbol{\begin{bmatrix}0&-2\\-2&0\\\end{bmatrix} }\)
C.   \(\small\boldsymbol{\begin{bmatrix}0&-\frac 12\\-\frac 12&0\\\end{bmatrix} }\)
D.   \(\small\boldsymbol{\begin{bmatrix}2&0\\0&2\\\end{bmatrix} }\)
E.   \(\text{doesn't exist}\)

Oplossing - Solution

\( \begin{bmatrix}a&b\\c&d\end{bmatrix}^{-1}=\frac{1}{\begin{vmatrix} a&b\\c&d \end{vmatrix}} \begin{bmatrix}d & -b \\-c & a\end{bmatrix}\\ \text{op voorwaarde dat de determinant (noemer) niet nul is}\\ \begin{bmatrix} 0 & 2 \\ 2 & 0 \end{bmatrix}^{-1} =\frac{1}{\begin{vmatrix} 0&2\\2&0\end{vmatrix}} \begin{bmatrix}0&-2\\-2&0\end{bmatrix} =\frac{1}{-4} \begin{bmatrix}0&-2\\-2&0\end{bmatrix} =\begin{bmatrix}0&\frac12\\\frac12&0\end{bmatrix}\\ \)
gricha