Question

For what value of x, the following matrix is singular? \( [−124x]
\)

Answer 1

Answer:

x = -8

I hope this is helpful.

Step-by-step explanation:

It's not clear to me, but I think the matrix in question is

$\displaystyle\left(\begin{array}{cc}-1&2\\4&x\end{array}\right)$

The matrix is singular

<=> the determinant = 0

<=> (-1)(x) - (2)(4) = 0

<=> -x - 8 = 0

<=> x = -8

Answer 2

The value of x, for which the following matrix is singular \( [−124x]

\) is given as follows,

A condition for a square matrix to be singular is that, the determinant should be zero.

Therefore, let us consider the given matrix,

$S = \begin{pmatrix}-1&2\\ 4&x\end{pmatrix}$

$\Rightarrow \begin{vmatrix}-1&2\\ 4&x\end{vmatrix} = 0$

$\left(-1\right)x-2\cdot \:4 = 0$

$-x-8=0$

$-x=8$

∴ x = - 8

The value of x for which the given matrix is singular is x = -8.