Math Problem Statement

Jika A = \( \begin{pmatrix} 2 & 5 \\ 1 & 3 \end{pmatrix} \) dan B = \( \begin{pmatrix} -2 & 5 \\ 2 & -3 \end{pmatrix} \), maka determinan A x B adalah ....

Solution

To solve for the determinant of A×BA \times B, where:

A=(2513),B=(2523)A = \begin{pmatrix} 2 & 5 \\ 1 & 3 \end{pmatrix}, \quad B = \begin{pmatrix} -2 & 5 \\ 2 & -3 \end{pmatrix}

The property of determinants states that:

det(A×B)=det(A)×det(B)\text{det}(A \times B) = \text{det}(A) \times \text{det}(B)

Step 1: Find the determinant of matrix AA

det(A)=(2×3)(5×1)=65=1\text{det}(A) = (2 \times 3) - (5 \times 1) = 6 - 5 = 1

Step 2: Find the determinant of matrix BB

det(B)=(2×3)(5×2)=610=4\text{det}(B) = (-2 \times -3) - (5 \times 2) = 6 - 10 = -4

Step 3: Calculate the determinant of A×BA \times B

det(A×B)=det(A)×det(B)=1×(4)=4\text{det}(A \times B) = \text{det}(A) \times \text{det}(B) = 1 \times (-4) = -4

Therefore, the determinant of A×BA \times B is 4-4.

The correct answer is d. -4.

Would you like more details or have any questions? Here are some related questions for further practice:

  1. How do you compute the determinant of a 3x3 matrix?
  2. What is the determinant of a diagonal matrix?
  3. Can a matrix with a zero determinant be inverted?
  4. How does the determinant change when two rows of a matrix are swapped?
  5. What are the properties of the determinant in relation to matrix multiplication?

Tip: The determinant of a product of two matrices is always the product of their individual determinants.

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Math Problem Analysis

Mathematical Concepts

Linear Algebra
Determinants
Matrix Multiplication

Formulas

det(A x B) = det(A) x det(B)
det(A) = (a11 * a22) - (a12 * a21)
det(B) = (b11 * b22) - (b12 * b21)

Theorems

Multiplicative Property of Determinants

Suitable Grade Level

Grades 10-12