The determinant of a 2 x 2 matrix - Matrices

The determinant of a 2 x 2 matrix

In this lesson, we will learn how to find a determinant of a 2 x 2 matrix. To find the determinant, we multiply the top left entry and bottom right entry and subtract it with the product of the top right entry and bottom left entry. We will use these determinants later on in the course to show if a matrix is invertible. We will also use it to find inverses of 2 x 2 matrices.

Lessons

Notes:
Let the matrix matrix X = a b c d, where a,b,c,a, b, c, and dd are all numbers. We denote the determinant of XX to be det(X)(X). To find the determinant of a 2 x 2 matrix we compute the following:

det(X)=adbc(X)=ad-bc
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The determinant of a 2 x 2 matrix

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