Math Problem Statement

What is the maximum possible discriminant for a 3x3 matrix with values ranging from -10 to 10

Solution

The "discriminant" is a concept generally used in relation to polynomials and quadratic equations, rather than directly to matrices. However, based on your question, I believe you're referring to the determinant of a 3x3 matrix, which is a common measure of a matrix's properties. The determinant provides information about a matrix, including whether it is invertible and the volume scaling factor of the linear transformation it represents.

For a 3x3 matrix with entries ranging from -10 to 10, the maximum possible value of the determinant can be calculated by considering the matrix with entries that maximize the determinant formula.

The determinant det(A)\text{det}(A) of a 3x3 matrix A=(abcdefghi)A = \begin{pmatrix} a & b & c \\ d & e & f \\ g & h & i \end{pmatrix} is given by:

det(A)=a(eifh)b(difg)+c(dheg)\text{det}(A) = a(ei - fh) - b(di - fg) + c(dh - eg)

To maximize the determinant, we need to select values that maximize each term. Setting the entries to the extreme values of the range [10,10][-10, 10] is a way to approach this. Using ±10\pm 10 for the matrix elements can result in a maximum value.

For example, consider this matrix:

A=(100001000010)A = \begin{pmatrix} 10 & 0 & 0 \\ 0 & 10 & 0 \\ 0 & 0 & 10 \end{pmatrix}

The determinant of this matrix is:

det(A)=10×(10×100×0)0×(0×100×0)+0×(0×010×0)\text{det}(A) = 10 \times (10 \times 10 - 0 \times 0) - 0 \times (0 \times 10 - 0 \times 0) + 0 \times (0 \times 0 - 10 \times 0) det(A)=10×(100)=1000\text{det}(A) = 10 \times (100) = 1000

Thus, the maximum possible determinant of a 3x3 matrix with entries ranging from -10 to 10 is 1000\boxed{1000}.

Would you like more details about matrix determinants or the properties they reveal? Here are five related questions to deepen the understanding:

  1. How does the determinant of a matrix relate to its invertibility?
  2. What is the geometric interpretation of the determinant in 2D and 3D?
  3. How does the sign of the determinant affect the properties of a matrix?
  4. What happens to the determinant if you swap rows or columns of a matrix?
  5. Can the determinant be used to solve systems of linear equations using Cramer's Rule?

Tip: The determinant of a matrix changes sign if you swap two rows or two columns.

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Math Problem Analysis

Mathematical Concepts

Linear Algebra
Determinants
Matrix Properties

Formulas

det(A) = a(ei - fh) - b(di - fg) + c(dh - eg)

Theorems

Properties of Determinants
Matrix Invertibility

Suitable Grade Level

Grades 10-12