# Finding the Determinant of a 2×2 Matrix

Determinants are useful properties of square matrices, but can involve a lot of computation. A 2×2 determinant is much easier to compute than the determinants of larger matrices, like 3×3 matrices. To find a 2×2 determinant we use a simple formula that uses the entries of the 2×2 matrix. 2×2 determinants can be used to find the area of a parallelogram and to determine invertibility of a 2×2 matrix.

Related Topics:
Matrices, Inverse of a 2×2 Matrix, Determinant of a 3×3 Matrix

### Determinant of a 2×2 Matrix

Before we can find the inverse of a matrix, we need to first learn how to get the determinant of a matrix.

.

Example:

Solution:

Example:

Solution:

This video shows how to find the determinant of a 2×2 matrix, and solve a few related problems.

This video explains the formula used to determine the inverse of a 2×2 matrix, if one exists.
This video provides two examples of calculating a 2×2 determinant. One example contains fractions.

Further lessons on determinants of matrices.
Another video on the determinant of a 2×2 matrix

Rotate to landscape screen format on a mobile phone or small tablet to use the Mathway widget, a free math problem solver that answers your questions with step-by-step explanations.

You can use the free Mathway calculator and problem solver below to practice Algebra or other math topics. Try the given examples, or type in your own problem and check your answer with the step-by-step explanations.