Math Problem Statement
reverse engineer a matrix from a span of Nullspace (A) = (-2, -1, 1, 0, 0) , (-3, 2, 0, -2, 1)
Solution
To reverse engineer a matrix given the span of its null space, we start by recognizing that the null space vectors form a basis for the null space of . In other words, each of these vectors is a solution to the homogeneous system .
The two null space vectors are:
These vectors tell us that:
To reverse engineer the matrix , we can construct by creating a matrix whose rows are orthogonal to both and . Since the null space is spanned by these two vectors, must have at least three rows (because the dimension of the null space is 2 and is underdetermined with respect to the number of constraints).
Step-by-Step Construction:
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Write the null space vectors as columns of a matrix:
\begin{pmatrix} -2 & -3 \\ -1 & 2 \\ 1 & 0 \\ 0 & -2 \\ 0 & 1 \end{pmatrix}$$ This matrix $$N$$ represents the null space of the matrix $$A$$. -
Construct by finding a matrix whose row space is orthogonal to the column space of :
To find , we need to compute a matrix such that and , which means each row of must be orthogonal to both and .
We can solve for this by finding vectors orthogonal to both null space vectors.
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Compute the matrix : Let's consider the orthogonal complement of the null space. For simplicity, we assume that is a matrix (since the null space has dimension 2, the row space must have dimension 3).
One possible matrix could be constructed using the row reduction process or by finding the orthogonal complement directly. Here's a potential form of the matrix:
\begin{pmatrix} 1 & 0 & 2 & 0 & 0 \\ 0 & 1 & 1 & 0 & 0 \\ 0 & 0 & 0 & 2 & 1 \end{pmatrix}$$ This matrix has the required property that: $$A \mathbf{v}_1 = 0 \quad \text{and} \quad A \mathbf{v}_2 = 0$$
Final Answer:
The matrix whose null space is spanned by the vectors and is:
\begin{pmatrix} 1 & 0 & 2 & 0 & 0 \\ 0 & 1 & 1 & 0 & 0 \\ 0 & 0 & 0 & 2 & 1 \end{pmatrix}$$ Let me know if you need more details on this process. --- Would you like further explanation on this? Here are 5 related questions to explore: 1. What is the significance of the null space in linear algebra? 2. How do you find the orthogonal complement of a vector space? 3. What is the relationship between the rank of a matrix and the null space? 4. Can the null space determine the uniqueness of the matrix $$A$$? 5. How can the null space help in solving systems of linear equations? **Tip:** The dimension of the null space is called the "nullity" of the matrix, and it provides important information about the number of solutions to the system $$A\mathbf{x} = 0$$.Ask a new question for Free
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Math Problem Analysis
Mathematical Concepts
Linear Algebra
Null Space
Matrix Construction
Orthogonality
Formulas
A * v = 0 (where v is a vector from the null space)
Theorems
Rank-Nullity Theorem
Orthogonality in Vector Spaces
Suitable Grade Level
Undergraduate Level
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