Math Problem Statement

Find matrix C where C = A^2 - (AB) + 3E, with matrices A and B provided.

Solution

The problem in the image provides two matrices AA and BB, and asks to find the matrix CC, where:

C=A2(AB)+3EC = A^2 - (AB) + 3E

Here:

  • A2A^2 is the square of matrix AA (i.e., A×AA \times A).
  • ABAB is the product of matrices AA and BB.
  • EE is the identity matrix, and multiplying it by 3 gives 3E3E.

The matrices provided are: A=(5601),B=(1132)A = \begin{pmatrix} 5 & -6 \\ 0 & -1 \end{pmatrix}, \quad B = \begin{pmatrix} -1 & 1 \\ 3 & 2 \end{pmatrix}

Step-by-step solution:

  1. Calculate A2A^2:

A2=A×A=(5601)×(5601)A^2 = A \times A = \begin{pmatrix} 5 & -6 \\ 0 & -1 \end{pmatrix} \times \begin{pmatrix} 5 & -6 \\ 0 & -1 \end{pmatrix}

Perform the matrix multiplication:

A2=((5×5+(6)×0)(5×(6)+(6)×(1))(0×5+(1)×0)(0×(6)+(1)×(1)))A^2 = \begin{pmatrix} (5 \times 5 + (-6) \times 0) & (5 \times (-6) + (-6) \times (-1)) \\ (0 \times 5 + (-1) \times 0) & (0 \times (-6) + (-1) \times (-1)) \end{pmatrix} A2=(2530+601)=(252401)A^2 = \begin{pmatrix} 25 & -30 + 6 \\ 0 & 1 \end{pmatrix} = \begin{pmatrix} 25 & -24 \\ 0 & 1 \end{pmatrix}

  1. Calculate ABAB:

AB=(5601)×(1132)AB = \begin{pmatrix} 5 & -6 \\ 0 & -1 \end{pmatrix} \times \begin{pmatrix} -1 & 1 \\ 3 & 2 \end{pmatrix}

Perform the matrix multiplication:

AB=((5×(1)+(6)×3)(5×1+(6)×2)(0×(1)+(1)×3)(0×1+(1)×2))AB = \begin{pmatrix} (5 \times (-1) + (-6) \times 3) & (5 \times 1 + (-6) \times 2) \\ (0 \times (-1) + (-1) \times 3) & (0 \times 1 + (-1) \times 2) \end{pmatrix} AB=(5185120302)=(23732)AB = \begin{pmatrix} -5 - 18 & 5 - 12 \\ 0 - 3 & 0 - 2 \end{pmatrix} = \begin{pmatrix} -23 & -7 \\ -3 & -2 \end{pmatrix}

  1. Find 3E3E:

The identity matrix EE is a 2x2 matrix:

E=(1001)E = \begin{pmatrix} 1 & 0 \\ 0 & 1 \end{pmatrix}

Multiplying by 3:

3E=3×(1001)=(3003)3E = 3 \times \begin{pmatrix} 1 & 0 \\ 0 & 1 \end{pmatrix} = \begin{pmatrix} 3 & 0 \\ 0 & 3 \end{pmatrix}

  1. Calculate C=A2(AB)+3EC = A^2 - (AB) + 3E:

Now, subtract ABAB from A2A^2 and add 3E3E:

C=(252401)(23732)+(3003)C = \begin{pmatrix} 25 & -24 \\ 0 & 1 \end{pmatrix} - \begin{pmatrix} -23 & -7 \\ -3 & -2 \end{pmatrix} + \begin{pmatrix} 3 & 0 \\ 0 & 3 \end{pmatrix}

First, subtract:

A2AB=(25(23)24(7)0(3)1(2))=(481733)A^2 - AB = \begin{pmatrix} 25 - (-23) & -24 - (-7) \\ 0 - (-3) & 1 - (-2) \end{pmatrix} = \begin{pmatrix} 48 & -17 \\ 3 & 3 \end{pmatrix}

Now, add 3E3E:

C=(481733)+(3003)=(48+317+03+03+3)C = \begin{pmatrix} 48 & -17 \\ 3 & 3 \end{pmatrix} + \begin{pmatrix} 3 & 0 \\ 0 & 3 \end{pmatrix} = \begin{pmatrix} 48 + 3 & -17 + 0 \\ 3 + 0 & 3 + 3 \end{pmatrix}

C=(511736)C = \begin{pmatrix} 51 & -17 \\ 3 & 6 \end{pmatrix}

Final Answer:

C=(511736)C = \begin{pmatrix} 51 & -17 \\ 3 & 6 \end{pmatrix}

Let me know if you need any further details or clarifications!


Here are 5 related questions for practice:

  1. How would you calculate A3A^3 using the matrix AA provided?
  2. Can you compute the determinant of matrix AA?
  3. How would the solution change if BB was a 3x2 matrix?
  4. What properties do the identity matrix EE and its multiples have?
  5. What is the inverse of matrix AA (if it exists)?

Tip: Always double-check your matrix multiplications row by column to avoid simple errors.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Matrix multiplication
Matrix addition
Identity matrix

Formulas

C = A^2 - (AB) + 3E
A^2 = A × A
AB = A × B
E is the identity matrix

Theorems

Matrix multiplication rules
Properties of the identity matrix

Suitable Grade Level

Grades 10-12