Question

Find the determinant of the following matrix. A =
-2 6
3 5​

Answer 1

`|A| = - 28`

Explanation:

Given

`A = \left[\begin{array}{cc}-2&6\\3&5\end{array}\right]`

Required

Determine the determinant

For a two by two matrix, A such that:

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

The determinant |A| is:

`|A| = a * d - b * c`

So, in

`A = \left[\begin{array}{cc}-2&6\\3&5\end{array}\right]`

The determinant is:

`|A| = -2 * 5 - 6 * 3`

`|A| = -10 - 18`

`|A| = - 28`