Question

Find the determinant of the given matrix.

Answer 1

Answer:

The determinant of the given matrix is:

                      a)   -42

Step-by-step explanation:

We are given a matrix let A as:

$A=\left[\begin{array}{ccc}5&4\\8&-2\end{array}\right]$

Determinant of a matrix--

The determinant of a 2×2 i.e. a square matrix of order 2 is calculated as follows:

If:

$A=\left[\begin{array}{ccc}a&b\\c&d\end{array}\right]$

then the determinant denoted by det(A) or |A| is given by:

$det(A)=ad-bc$

Here a=5, b=4 , c=8 and d= -2

Hence, the determinant is given by:

$det(A)=5\times (-2)-4\times 8\\\\i.e.\\\\det(A)=-10-32\\\\i.e.\\\\det(A)=-42$

             The correct answer is: Option: a)

Answer 2

Answer: -42

Step-by-step explanation: 2*2 matrices are easy to find the determinant with. Its just ad-bc, so (5*-2)-(4*8), which is -42