# Determinant of 3x3 Matrices, 2x2 Matrix, Precalculus Video Tutorial | Summary and Q&A

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April 25, 2017
by
The Organic Chemistry Tutor
Determinant of 3x3 Matrices, 2x2 Matrix, Precalculus Video Tutorial

## TL;DR

This video explains how to find the determinants of 2x2 and 3x3 matrices using the appropriate formulas.

## Key Insights

• ❓ The determinant of a 2x2 matrix is found by applying a simple formula: (ad) - (bc).
• 🍳 The determinant of a 3x3 matrix involves breaking it down into three 2x2 matrices and evaluating them.
• 🤘 The process of finding the determinant of a 3x3 matrix requires careful attention to signs and applying the correct formulas.
• ❓ Practice and examples are important for understanding and calculating determinants accurately.
• 💁 The determinant of a matrix provides important information about its properties and possible solutions to equations involving the matrix.
• 🎮 The formulas and methods described in the video can be applied to matrices of any size, not just 2x2 and 3x3 matrices.
• 🈸 Calculating determinants is an essential skill in linear algebra and in various applications of mathematics.

## Transcript

in this video we're going to focus on finding the determinant of a two by two matrix and also of a three by three matrix so let's start with the basics the two by two matrix here let's say this is uh a c b and d so it's going to be equal to a times d minus b times c that's how you can find the determinant of a two by two matrix so let's work on som... Read More

### Q: How do you find the determinant of a 2x2 matrix?

To find the determinant of a 2x2 matrix, you multiply the top left element by the bottom right element and subtract the product of the bottom left and top right elements.

### Q: What is the formula for finding the determinant of a 3x3 matrix?

The formula for finding the determinant of a 3x3 matrix involves breaking it down into three 2x2 matrices and evaluating each one individually, using addition and subtraction as specified.

### Q: Can you explain the process of simplifying a 3x3 matrix into three 2x2 matrices?

To simplify a 3x3 matrix, eliminate the first row and first column to create the first 2x2 matrix. Repeat the process for the remaining two rows and columns to create two more 2x2 matrices.

### Q: How do you calculate the determinant of a 3x3 matrix using the simplified 2x2 matrices?

To calculate the determinant of a 3x3 matrix using the simplified 2x2 matrices, multiply each element of the original matrix by the determinant of its respective 2x2 matrix, and correctly apply the signs specified in the formula.

## Summary & Key Takeaways

• The determinant of a 2x2 matrix is found by subtracting the product of the bottom left and top right elements from the product of the top left and bottom right elements.

• The determinant of a 3x3 matrix involves breaking it down into three 2x2 matrices and evaluating each one individually.

• The determinants of the 2x2 and 3x3 matrices can be calculated using the given formulas and examples provided.