Math Problem Statement

Consider the system Ax = b where A = [[-1, 3], [-4, 12]] and b = [[1], [-1]]. A basis for the null space of A is given by [[3], [1]] and x = [[-1], [0]] is a particular solution. Use this information to find the row space solution x_r to Ax = b.

Solution

We are given the system Ax=bAx = b, where:

A=[13412],b=[11]A = \begin{bmatrix} -1 & 3 \\ -4 & 12 \end{bmatrix}, \quad b = \begin{bmatrix} 1 \\ -1 \end{bmatrix} A basis for the null space of AA is given by: [31]\begin{bmatrix} 3 \\ 1 \end{bmatrix} and a particular solution to Ax=bAx = b is: xp=[10]x_p = \begin{bmatrix} -1 \\ 0 \end{bmatrix}

We need to find the row space solution xrx_r for the equation Ax=bAx = b.

Solution

The general solution for the equation Ax=bAx = b can be written as: x=xp+xnx = x_p + x_n where xpx_p is a particular solution to the system, and xnx_n is any solution in the null space of AA.

Given that a basis for the null space is [31]\begin{bmatrix} 3 \\ 1 \end{bmatrix}, we can express xnx_n as: xn=k[31]x_n = k \begin{bmatrix} 3 \\ 1 \end{bmatrix} for some scalar kk.

The row space solution xrx_r represents the component of xx that lies in the row space of AA. Since xp=[10]x_p = \begin{bmatrix} -1 \\ 0 \end{bmatrix} is already a solution to the system, and it does not lie in the null space of AA, it is the row space solution.

Therefore, the row space solution xrx_r is: xr=[10]x_r = \begin{bmatrix} -1 \\ 0 \end{bmatrix}

Would you like more details on this explanation or have any questions?

Related Questions

  1. What is the definition of the row space of a matrix?
  2. How do you find a particular solution for a linear system Ax=bAx = b?
  3. What are the steps to find the null space of a matrix?
  4. Why is the null space important when solving linear equations?
  5. How can we verify if a given vector is a solution to the equation Ax=bAx = b?

Tip

When solving a system of linear equations, it's helpful to check both the particular solution and the null space solution to ensure the completeness of the general solution.

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Math Problem Analysis

Mathematical Concepts

Linear Algebra
Systems of Linear Equations
Row Space
Null Space

Formulas

Ax = b
x = x_p + x_n
Null space: N(A) = {v | Av = 0}

Theorems

Null Space Theorem
Row Space Theorem
General Solution for Ax = b

Suitable Grade Level

Undergraduate Level (Linear Algebra)