How To Find The Determinant Of 2x2 Matrix.

The determinant of a matrix is a special number that can be calculated from a square matrix.

A Matrix is a matrix that has equal number of rows and columns
Example; a matrix that has 2 Rows and 2 Columns is square matrix of the order 2x2

The determinant helps us find the inverse of a matrix, tells us things about the matrix that are useful in systems of linear equations, calculus and more.

The symbol for determinant is two vertical lines either side, example; |A| or Det(A)

Calculating the Determinant

First of all the matrix must be square (i.e. have the same number of rows as columns). Then it is just basic arithmetic. Here is how:

For a 2×2 Matrix A

The determinant of A equals to (a₁₁•a₂₂-a₂₁•a₁₂) where a₁₁ is the first row first column element, a₁₂ is the first row second column element, a₂₁ is the second row first column element and a₂₂ is the second row second column element.

It is easy to remember when you think of a cross Multiplication.