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Evaluate Determinants of 3×3 Matrices

In linear algebra, a determinant is a scalar quantity that can be determined using the square matrix components. It encodes some of the linear transformation's features and is denoted by, , det (A), or |A|.

The determinant can be considered the function associated with each square matrix with a unique number; the number can be real or complex depending on the nature of the matrix.  The determinant is only applicable to square matrices, such as 2×2, 3×3, and 4×4.

Square matrix: It is defined as a matrix with the same rows and columns.

If matrix A = , then the determinant of a square matrix A represent as | A | =  = det (A)

How to Solve For Determinants 

Evaluate Determinants of 3×3 Matrices or matrix of order three

Step 5) Calculate the value of the determinants

Application of 3×3 Determinants

1)   Determinants of the matrix are used to find out the inverse of the matrix. If the determinant of any square matrix exists, which implies the inverse of that matrix also exists, we can find the inverse of that matrix by using cofactors.

2)  Determinants are used to calculate the eigenvalue of any system in quantum computing.

3)   It is also used to calculate the variance in any given system.

4)  It is used to calculate the solution of any linear system, e.g. in the crammers rule, we have to use determinants to find the solution of a given linear system having the same number of variables and equations.

5)  It is also used to check whether a triangle is collinear or not. If the area of the triangle is zero, then the triangle is collinear.

6)  If the triangle’s vertices are known, it is possible to calculate the area of the triangle in determinant form using them. Suppose we have a triangle ABC with three vertices:

7) Determinant applications are used in the polynomial interpolation to various degrees.

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Frequently asked questions

Get answers to the most common queries related to the NDA Examination Preparation.

Can a matrix of order 3 × 4 have determinants.

Ans : No, the concept of the determinant is only applicable for the square matrix which contains th...Read full

Determinant is a scalar quantity or vector quantity?

Ans : Determinant is a scalar quantity. It is the value associated with each square matrix....Read full

Evaluate determinants of 3x3 matrices given below.

Ans : Given matrix is a dimension of 3×3, the Formula for determining the matrix of 3×3 is  ...Read full

Evaluate the determinant 3×3 matrix of the given matrix A

Ans : Given matrix is a dimension of 3×3, the Formula for determining the matrix of 3×3 is  ...Read full

Find the area of the triangle ABC in a determinant form whose vertices are A(2, 1), B(3, -3), and C(4, 0). ( Hint: You have to evaluate determinants of 3x3 Matrices )

Ans : To find the area of triangle ABC, we will use the formula, Area of triangle ABC...Read full