Math Problem Statement

اختر الاجابه الصحيحه فقط

اختر الاجابة الصحيحة فقط

Solution

The question asks for the correct choice regarding the matrix A=(235405579)A = \begin{pmatrix} 2 & 3 & 5 \\ 4 & 0 & 5 \\ 5 & 7 & -9 \end{pmatrix} and the value of det(A)\det(A) (the determinant of matrix AA).

To solve for det(A)\det(A), let's compute the determinant using cofactor expansion along the first row:

det(A)=2det(0579)3det(4559)+5det(4057)\det(A) = 2 \cdot \det\begin{pmatrix} 0 & 5 \\ 7 & -9 \end{pmatrix} - 3 \cdot \det\begin{pmatrix} 4 & 5 \\ 5 & -9 \end{pmatrix} + 5 \cdot \det\begin{pmatrix} 4 & 0 \\ 5 & 7 \end{pmatrix}

Let me compute this.The determinant of matrix AA is det(A)=253\det(A) = 253.

Thus, the correct answer for det(A)\det(A) is 253, which matches the option marked as "undefined" in the image. However, this is not correct because the determinant is clearly defined and equals 253.

Let me know if you want more details or have any questions. Here are some related questions:

  1. How is the determinant of a matrix related to its invertibility?
  2. Can a matrix with a zero determinant have an inverse?
  3. What properties do we need for a matrix determinant to be undefined?
  4. How does the size of the matrix affect the complexity of calculating the determinant?
  5. How can we interpret the determinant geometrically?

Tip: Always double-check the signs during cofactor expansion when computing a determinant manually!

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Math Problem Analysis

Mathematical Concepts

Linear Algebra
Determinants
Matrix Theory

Formulas

det(A) = a(ei − fh) − b(di − fg) + c(dh − eg)
Cofactor Expansion

Theorems

Determinant Theorem
Cofactor Expansion

Suitable Grade Level

Undergraduate (Math/Engineering)