Math Problem Statement

Bantu ngerjain tugas mtk

Solution

Let's work through the math problems from the image. Here's a step-by-step solution for each question:

1. Find the result of A=[3124]A = \begin{bmatrix} 3 & 1 \\ -2 & 4 \end{bmatrix} and C=[1012]C = \begin{bmatrix} 1 & 0 \\ -1 & 2 \end{bmatrix}:

(a) Calculate A+CA + C:

A+C=[3124]+[1012]=[3+11+02+(1)4+2]=[4136]A + C = \begin{bmatrix} 3 & 1 \\ -2 & 4 \end{bmatrix} + \begin{bmatrix} 1 & 0 \\ -1 & 2 \end{bmatrix} = \begin{bmatrix} 3 + 1 & 1 + 0 \\ -2 + (-1) & 4 + 2 \end{bmatrix} = \begin{bmatrix} 4 & 1 \\ -3 & 6 \end{bmatrix}

(b) Calculate 2A3C2A - 3C:

2A=2×[3124]=[6248]2A = 2 \times \begin{bmatrix} 3 & 1 \\ -2 & 4 \end{bmatrix} = \begin{bmatrix} 6 & 2 \\ -4 & 8 \end{bmatrix}

3C=3×[1012]=[3036]3C = 3 \times \begin{bmatrix} 1 & 0 \\ -1 & 2 \end{bmatrix} = \begin{bmatrix} 3 & 0 \\ -3 & 6 \end{bmatrix}

2A3C=[6248][3036]=[63204(3)86]=[3212]2A - 3C = \begin{bmatrix} 6 & 2 \\ -4 & 8 \end{bmatrix} - \begin{bmatrix} 3 & 0 \\ -3 & 6 \end{bmatrix} = \begin{bmatrix} 6 - 3 & 2 - 0 \\ -4 - (-3) & 8 - 6 \end{bmatrix} = \begin{bmatrix} 3 & 2 \\ -1 & 2 \end{bmatrix}

2. Find the result of B=[1230]B = \begin{bmatrix} 1 & -2 \\ 3 & 0 \end{bmatrix}:

(a) Calculate BTB^T:

The transpose of BB is:

BT=[1320]B^T = \begin{bmatrix} 1 & 3 \\ -2 & 0 \end{bmatrix}

(b) Calculate 3A2B3A - 2B:

3A=3×[3124]=[93612]3A = 3 \times \begin{bmatrix} 3 & 1 \\ -2 & 4 \end{bmatrix} = \begin{bmatrix} 9 & 3 \\ -6 & 12 \end{bmatrix}

2B=2×[1230]=[2460]2B = 2 \times \begin{bmatrix} 1 & -2 \\ 3 & 0 \end{bmatrix} = \begin{bmatrix} 2 & -4 \\ 6 & 0 \end{bmatrix}

3A2B=[93612][2460]=[923(4)66120]=[771212]3A - 2B = \begin{bmatrix} 9 & 3 \\ -6 & 12 \end{bmatrix} - \begin{bmatrix} 2 & -4 \\ 6 & 0 \end{bmatrix} = \begin{bmatrix} 9 - 2 & 3 - (-4) \\ -6 - 6 & 12 - 0 \end{bmatrix} = \begin{bmatrix} 7 & 7 \\ -12 & 12 \end{bmatrix}

3. Given matrix D=[4205]D = \begin{bmatrix} 4 & 2 \\ 0 & 5 \end{bmatrix}, find D1D^{-1}:

To find D1D^{-1}:

  1. Calculate the determinant of DD:

Det(D)=(4)(5)(2)(0)=20\text{Det}(D) = (4)(5) - (2)(0) = 20

  1. Find the adjoint of DD:

Adj(D)=[5204]\text{Adj}(D) = \begin{bmatrix} 5 & -2 \\ 0 & 4 \end{bmatrix}

  1. Divide by the determinant:

D1=120×[5204]=[520220020420]=[14110015]D^{-1} = \frac{1}{20} \times \begin{bmatrix} 5 & -2 \\ 0 & 4 \end{bmatrix} = \begin{bmatrix} \frac{5}{20} & \frac{-2}{20} \\ \frac{0}{20} & \frac{4}{20} \end{bmatrix} = \begin{bmatrix} \frac{1}{4} & -\frac{1}{10} \\ 0 & \frac{1}{5} \end{bmatrix}

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

Related Questions:

  1. How do you find the inverse of a matrix if the determinant is zero?
  2. What are the properties of matrix addition and subtraction?
  3. How do you multiply two matrices together?
  4. What is the significance of the transpose of a matrix?
  5. How do you find the determinant of a 3x3 matrix?

Tip: Always check if a matrix is invertible by ensuring its determinant is not zero.

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Math Problem Analysis

Mathematical Concepts

Matrices
Matrix Operations
Matrix Inverse

Formulas

Matrix addition
Matrix subtraction
Matrix multiplication
Matrix transpose
Determinant formula

Theorems

Properties of matrices
Inverse matrix theorem

Suitable Grade Level

High School