For the matrix \[{\text{A}} = \left[ {\begin{array}{*{20}{c}} 3&{ – 2}&2 \\ 0&{ – 2}&1 \\ 0&0&1 \end{array}} \right],\] one of the eigen values is equal to -2. Which of the following is an eigen vector? A. \[\left[ {\begin{array}{*{20}{c}} 3 \\ { – 2} \\ 1 \end{array}} \right]\] B. \[\left[ {\begin{array}{*{20}{c}} { – 3} \\ 2 \\ { – 1} \end{array}} \right]\] C. \[\left[ {\begin{array}{*{20}{c}} 1 \\ { – 2} \\ 3 \end{array}} \right]\] D. \[\left[ {\begin{array}{*{20}{c}} 2 \\ 5 \\ 0 \end{array}} \right]\]

”[left[
\]” option2=”\[\left[ {\begin{array}{*{20}{c}} { – 3} \\ 2 \\ { – 1} \end{array}} \right]\]” option3=”\[\left[ {\begin{array}{*{20}{c}} 1 \\ { – 2} \\ 3 \end{array}} \right]\]” option4=”\[\left[ {\begin{array}{*{20}{c}} 2 \\ 5 \\ 0 \end{array}} \right]\]” correct=”option1″]

The correct answer is $\boxed{\left[ {\begin{array}{*{20}{c}} 1 \ { – 2} \ 3 \end{array}} \right]}$.

An eigenvector of a matrix $A$ is a nonzero vector $v$ such that there exists a scalar $\lambda$, called the eigenvalue, such that $Av=\lambda v$.

To find the eigenvalues and eigenvectors of a matrix, we can use the following steps:

  1. Find the characteristic polynomial of $A$, which is the determinant of the matrix $|A-\lambda I|$.
  2. Solve the characteristic polynomial for $\lambda$.
  3. For each eigenvalue $\lambda$, find all vectors $v$ such that $Av=\lambda v$. These vectors are the eigenvectors of $A$ corresponding to the eigenvalue $\lambda$.

In this case, the characteristic polynomial of $A$ is $p(\lambda)=-\lambda^3+5\lambda^2-11\lambda+6$. We can factor this polynomial as follows:

$$p(\lambda)=(\lambda-2)^2(\lambda-3)$$

Therefore, the eigenvalues of $A$ are $2$ and $3$.

To find the eigenvectors corresponding to the eigenvalue $2$, we can solve the equation $A v = 2 v$. This gives us the system of equations:

$$\begin{align}
3v_1-2v_2+2v_3 &= 0 \
0v_1-2v_2+v_3 &= 0 \
0v_1+0v_2+3v_3 &= 0
\end{align
}$$

Solving this system of equations, we find that the only solution is $v=\left[ {\begin{array}{*{20}{c}} 1 \ { – 2} \ 3 \end{array}} \right]$.

Therefore, the eigenvector of $A$ corresponding to the eigenvalue $2$ is $\boxed{\left[ {\begin{array}{*{20}{c}} 1 \ { – 2} \ 3 \end{array}} \right]}$.