Recent questions and answers in Linear Algebra

1 1 vote
2 2 answers
243
243 views
Two $n \times n$ matrices $A$ and $B$ have a common eigenvalue $2$, and the same corresponding nonzero eigenvector.Which of the following options is/are correct?(Note: $I...
1 1 vote
1 1 answer
154
154 views
Consider the system of linear equations: $A \boldsymbol{x}=\boldsymbol{b}$, where $A$ is an $n \times n$ matrix, and $\boldsymbol{x}$ and $\boldsymbol{b}$ are $n$-dimensi...
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1 1 answer
472
472 views
Given a system of equations: $x+2y+2z=b_1$ $5x+y+3z=b_2$ Which of the following is true regarding its ...
0 0 votes
2 2 answers
487
487 views
Let $v_{1}$ and $v_{2}$ be the two eigenvectors corresponding to distinct eigenvalues of a $3 \times 3$ real symmetric matrix. Which one of the following statements is tr...
0 0 votes
0 0 answers
76
76 views
$A$ is an $m \times m$ skew-symmetric matrix with real-valued entries, and $\boldsymbol{x}$ is an $m$-dimensional column vector with real-valued entries such that $\bolds...
0 0 votes
0 0 answers
95
95 views
Which one of the following statements is ALWAYS correct about a collection of $p$ column vectors, each having $n$ real-valued entries?If $p>n$, then the column vectors mu...
0 0 votes
0 0 answers
75
75 views
Consider an $n \times n$ orthogonal matrix $A$ with real entries and each column having unit Euclidean norm.Which of the following statements is/are correct?The value of ...
1 1 vote
1 1 answer
389
389 views
Let $\boldsymbol{A}=\left[\begin{array}{ccc}1 & 1 & 1 \\ -1 & -1 & -1 \\ 0 & 1 & -1\end{array}\right]$, and $\boldsymbol{b}=\left[\begin{array}{c}1 / 3 \\ -1 / 3 \\ 0\end...
2 2 votes
1 1 answer
760
760 views
For a given vector $\mathbf{w}=\left[\begin{array}{lll}1 & 2 & 3\end{array}\right]^{\mathrm{T}}$, the vector normal to the plane defined by $\mathbf{w}^{\mathrm{T}} \math...
0 0 votes
1 1 answer
1.2k
1.2k views
The sum of the eigenvalues of the matrix $A=\left[\begin{array}{ll}1 & 2 \\ 3 & 4\end{array}\right]^{2}$ is ____________(rounded off to the nearest integer).
0 0 votes
1 1 answer
312
312 views
Let $P=\left[\begin{array}{ccc}2 & 1 & 0 \\ -1 & 0 & 0 \\ 0 & 0 & 1\end{array}\right]$ and let $I$ be the identity matrix. Then $P^{2}$ is equal to$2 P-I$$P$$I$$P+I$
2 2 votes
1 1 answer
454
454 views
Consider a matrix $A = \begin{bmatrix} 1 & 0 & 0\\ 0 & 4 & -2\\ 0 & 1 & 1 \end{bmatrix}$.The matrix $A$ satisfies the equation $6A^{-1} = A^{2} + cA + dl$, where $c$ and ...
0 0 votes
1 1 answer
556
556 views
Let $A= \begin{bmatrix} 1 & 0 & -1 \\ -1 & 2 & 0 \\ 0 & 0 & -2 \end{bmatrix}$ and $B=A^3-A^2-4A+5I$, where $I$ is the $3 \times 3$ identify matrix. The determinant of $B$...
0 0 votes
1 1 answer
459
459 views
Given that $\textbf{A}= \begin{bmatrix} -5 & -3 \\ 2 & 0 \end{bmatrix}$ and $\textbf{I} = \begin{bmatrix} 1 & 0 \\ 0 & 1 \end{bmatrix}$, the value of $A^3$ is$15 \: \text...
0 0 votes
3 3 answers
2.8k
2.8k views
​​​​Which one of the following matrices has an inverse?$\left[\begin{array}{ccc}1 & 4 & 8 \\ 0 & 4 & 2 \\ 0.5 & 2 & 4\end{array}\right]$$\left[\begin{array}{lll}1 & 2 & 3...
0 0 votes
2 2 answers
1.2k
1.2k views
Let $A$ be a $10\times10$ matrix such that $A^{5}$ is a null matrix, and let $I$ be the $10\times10$ identity matrix. The determinant of $\text{A+I}$ is _________________...
1 1 vote
0 0 answers
687
687 views
In the figure, the vectors $\mathbf{u}$ and $\mathbf{v}$ are related as: $\mathbf{A u}=\mathbf{v}$ by a transformation matrix A. The correct choice of $\mathbf{A}$ is$\le...
0 0 votes
1 1 answer
1.2k
1.2k views
The number of purely real elements in a lower triangular representation of the given $3\times 3$ matrix, obtained through the given decomposition is ______________.$$\beg...
0 0 votes
0 0 answers
481
481 views
Consider a $3\times 3$ matrix $A$ whose $(i,j)$-th element, $a_{i,j} = \left ( i- j \right )^{3}$. Then the matrix $A$ will besymmetricskew-symmetricunitarynull
0 0 votes
0 0 answers
479
479 views
$e^{A}$ denotes the exponential of a square matrix $A$. Suppose $\lambda$ is an eigenvalue and $v$ is the corresponding eigen-vector of the matrix $A$.​​​​​​​Consider the...
0 0 votes
1 1 answer
939
939 views
Let $p$ and $q$ be real numbers such that $p^{2}+q^{2}=1$ . The eigenvalues of the matrix $\begin{bmatrix} p & q\\ q& -p \end{bmatrix}$are$1$ and $1$$1$ and $-1$$j$ and $...
0 0 votes
0 0 answers
306
306 views
$\\ P=\begin{pmatrix} -10\\ -1\\ 3 \end{pmatrix}^{T} Q=\begin{pmatrix} -2\\ -5\\ 9 \end{pmatrix}^{T} R=\begin{pmatrix} 2\\ -7\\ 12 \end{pmatrix}^{T} are\ three\ vectors.\...
0 0 votes
1 1 answer
829
829 views
The rank of the matrix, $M = \begin{bmatrix} 0 &1 &1 \\ 1& 0 &1 \\ 1& 1 & 0 \end{bmatrix}$, is ______________.
0 0 votes
1 answers 1 answer
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531 views
$M$ is $2 \times 2$ matrix with eigenvalues $4$ and $9.$ The eigenvalues of $M^{2}$ are$4$ and $9$$2$ and $3$$-2$ and $-3$$16$ and $81$
0 0 votes
0 0 answers
602
602 views
Consider a $2\times 2$ matrix $M=\begin{bmatrix} v_1 & v_2 \end{bmatrix}$, where $v_1$ and $v_2$ are the column vectors. Suppose $M^{-1}=\begin{bmatrix} u_1^T \\ u_2^T \e...
1 1 vote
1 1 answer
1.9k
1.9k views
Which one of the following statements is true for all real symmetric matrices?All the eigenvalues are real.All the eigenvalues are positive.All the eigenvalues are distin...
0 0 votes
0 0 answers
334
334 views
The state variable description of an LTI system is given by$$\begin{pmatrix} x_1 \\ x_2 \\ x_3 \end{pmatrix} = \begin{pmatrix} 0 & a_1 & 0 \\ 0 & 0 & a_2 \\ a_3 & 0 & 0 \...
0 0 votes
0 0 answers
521
521 views
Consider a non-singular $2 \times 2$ square matrix $\textbf{A}$. If $\text{trace}(\textbf{A})=4$ and $\text{trace}(\textbf{A}^2)=5$, the determinant of the matrix $\textb...
0 0 votes
0 0 answers
260
260 views
The eigenvalues of the matrix given below are$\begin{bmatrix}0 & 1 & 0\\ 0 & 0 & 1\\ 0 & -3 & -4\end{bmatrix}$$(0, -1, -3)$$(0, -2, -3)$$(0, 2, 3)$$(0, 1, 3)$
0 0 votes
0 0 answers
261
261 views
The matrix $A=\begin{bmatrix}\frac{3}{2} &0 & \frac{1}{2}\\ 0& -1 &0 \\ \frac{1}{2} & 0 & \frac{3}{2}\end{bmatrix}$ has three distinct eigenvalues and one of its eigenv...
0 0 votes
0 0 answers
458
458 views
The state variable formulation of a system is given as$\begin{bmatrix} x^\cdot_1 \\ x^\cdot_2 \end{bmatrix}=\begin{bmatrix} -2 & 0\\ 0 & -1 \end{bmatrix}\begin{bmatrix} x...
1 1 vote
0 0 answers
294
294 views
The state variable formulation of a system is given as$\begin{bmatrix} x^\cdot_1 \\ x^\cdot_2 \end{bmatrix}=\begin{bmatrix} -2 & 0\\ 0 & -1 \end{bmatrix}\begin{bmatrix} x...
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