Exploring the Relationship Between det(kA) and k^n detA

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In summary, the determinant of kA is equal to k^n times the determinant of A due to the scaling property, which holds for any square matrix and is used in many practical applications. This property can be proven by examining elementary matrices and also has connections to other determinant properties, such as the product rule and the transpose rule.
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why does det(kA)=(k^n)detA and not kdetA?
 
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The matrlix kA has a factor of k in every element. Each term in the determinant of an nXn matrix has n factors, so k comes in n times.
Therefore, det(kA)=k^n det(A).
 
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thank you very much!
 

FAQ: Exploring the Relationship Between det(kA) and k^n detA

1. Why is the determinant of kA equal to k^n times the determinant of A?

This is a fundamental property of determinants, known as the scaling property. It means that when a matrix is multiplied by a constant, the determinant is also multiplied by that constant raised to the power of the matrix's order (or size). In other words, if A is an n x n matrix and k is a constant, then det(kA) = k^n det(A).

2. How can we prove that det(kA) = k^n detA?

One way to prove this property is by showing that it holds for elementary matrices, which are matrices that represent elementary row operations. These operations include swapping two rows, multiplying a row by a constant, and adding a multiple of one row to another row. It can be shown that each of these operations affects the determinant in a predictable way, ultimately leading to the scaling property.

3. Can the property det(kA) = k^n detA be generalized to any type of matrix?

Yes, this property holds for any square matrix, regardless of its size or type. It is a fundamental property of determinants and holds true for all types of matrices, including real, complex, and even infinite-dimensional matrices.

4. How is the scaling property of determinants used in practical applications?

The scaling property of determinants is used in many areas of mathematics, physics, and engineering. For example, it is used to solve systems of linear equations, calculate the inverse of a matrix, and determine whether a linear transformation is invertible. It also has applications in areas such as computer graphics, cryptography, and statistics.

5. Are there any other properties of determinants that are related to the scaling property?

Yes, there are several other properties of determinants that are related to the scaling property. These include the fact that the determinant of the product of two matrices is equal to the product of their determinants, and that the determinant of the transpose of a matrix is equal to the determinant of the original matrix. These properties, along with the scaling property, are essential for understanding and working with determinants in various applications.

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