Recent questions tagged linear-algebra

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GATE EC 2021 | Question: 36
A real $2\times2$ non-singular matrix $A$ with repeated eigenvalue is given as $A=\begin{bmatrix} x & -3.0\\ 3.0 & 4.0 \end{bmatrix}$ where $x$ is a real positive number. The value of $x$ (rounded off to one decimal place) is ________________

asked Feb 20 in Linear Algebra by Arjun (4.4k points) | 12 views

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GATE ECE 2020 | Question: 26
Consider the following system of linear equations. $\begin{array}{llll} x_{1}+2x_{2}=b_{1} ; & 2x_{1}+4x_{2}=b_{2}; & 3x_{1}+7x_{2}=b_{3} ; & 3x_{1}+9x_{2}=b_{4} \end{array}$ Which one of the following conditions ensures that a solution exists for the above system? ... $b_{2}=2b_{1}$ and $3b_{1}-6b_{3}+b_{4}=0$ $b_{3}=2b_{1}$ and $3b_{1}-6b_{3}+b_{4}=0$

asked Feb 13, 2020 in Linear Algebra by jothee (1.8k points) | 26 views

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GATE ECE 2019 | Question: 17
The number of distinct eigenvalues of the matrix $A=\begin{bmatrix} 2&2&3&3\\0&1&1&1\\0&0&3&3\\0&0&0&2 \end{bmatrix}$ is equal to ____________.

asked Feb 12, 2019 in Linear Algebra by Arjun (4.4k points) | 59 views

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GATE ECE 2016 Set 3 | Question: 1
Consider a $2\times2$ sqaure matrix $\textbf{A}= \begin{bmatrix} \sigma &x\\ \omega &\sigma \end{bmatrix},$ where $x$ is unknown. If the eigen values of the matrix $\textbf{A}$ are $(\sigma + j\omega)$ and $(\sigma - j\omega)$, then $x$ is equal to $+j\omega$ $-j\omega$ $+\omega$ $-\omega$

asked Mar 28, 2018 in Linear Algebra by Milicevic3306 (15.8k points) | 27 views

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GATE ECE 2016 Set 2 | Question: 1
The value of $x$ for which the matrix $A= \begin{bmatrix} 3& 2 &4 \\ 9& 7 & 13\\ -6&-4 &-9+x \end{bmatrix}$ has zero as an eigenvalue is ________

asked Mar 28, 2018 in Linear Algebra by Milicevic3306 (15.8k points) | 18 views

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GATE ECE 2016 Set 2 | Question: 29
The matrix $A=\begin{bmatrix} a & 0 &3 &7 \\ 2& 5&1 &3 \\ 0& 0& 2 &4 \\ 0&0 & 0 &b \end{bmatrix}$ has $\text{det}(A) = 100$ and $\text{trace}(A) = 14$. The value of $\mid a-b \mid$ is ________

asked Mar 28, 2018 in Linear Algebra by Milicevic3306 (15.8k points) | 15 views

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GATE ECE 2016 Set 1 | Question: 1
Let $M^4$= $I$,(where $I$ denotes the identity matrix) and $ M \neq I$, $M^2\neq I$ and $M^3\neq I$. Then,for any natural number $k$, $M^{-1}$ equals: $M^{4k+1}$ $M^{4k+2}$ $M^{4k+3}$ $M^{4k}$

asked Mar 28, 2018 in Linear Algebra by Milicevic3306 (15.8k points) | 15 views

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GATE ECE 2016 Set 1 | Question: 27
A sequence $x[n]$ is specified as $\begin{bmatrix}x[n] \\x[n – 1]\end{bmatrix}=\begin{bmatrix}1&1\\1&0\end{bmatrix}^n\begin{bmatrix}1\\0\end{bmatrix}$,for $n \geq 2$. The initial conditions are $x[0] = 1$, $x[1] = 1$, and $x[n] = 0$ for $n < 0$. The value of $x[12]$ is _________

asked Mar 28, 2018 in Linear Algebra by Milicevic3306 (15.8k points) | 15 views

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GATE ECE 2015 Set 3 | Question: 1
For $A = \begin{bmatrix} 1 &\tan x \\ -\tan x &1 \end{bmatrix},$ the determinant of $A^{T}A^{-1}$ is $\sec^{2}x$ $\cos 4x$ $1$ $0$

asked Mar 28, 2018 in Linear Algebra by Milicevic3306 (15.8k points) | 13 views

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GATE ECE 2015 Set 2 | Question: 2
The value of $x$ for which all the eigen-values of the matrix given below are real is $\begin{bmatrix} 10&5+j &4 \\ x&20 &2 \\4 &2 &-10 \end{bmatrix}$ $5+j$ $5-j$ $1-5j$ $1+5j$

asked Mar 28, 2018 in Linear Algebra by Milicevic3306 (15.8k points) | 11 views

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GATE ECE 2015 Set 2 | Question: 46
The state variable representation of a system is given as $\dot{x} = \begin{bmatrix} 0 &1 \\ 0 &-1 \end{bmatrix}\: ; x(0)=\begin{bmatrix} 1\\0 \end{bmatrix}$ $y=\begin{bmatrix} 0 &1 \end{bmatrix} x$ The response $y(t)$ is $\sin(t)$ $1-e^{t}$ $1-\cos(t)$ $0$

asked Mar 28, 2018 in Linear Algebra by Milicevic3306 (15.8k points) | 23 views

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GATE ECE 2015 Set 1 | Question: 1
Consider a system of linear equations: $x-2y+3z=-1, \\ x-3y+4z=1, \text{ and } \\ -2x+4y-6z=k.$ The value of $k$ for which the system has infinitely many solutions is ___________

asked Mar 28, 2018 in Linear Algebra by Milicevic3306 (15.8k points) | 20 views

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GATE ECE 2015 Set 1 | Question: 5
The value of $p$ such that the vector $\begin{bmatrix} 1 \\ 2 \\ 3 \end{bmatrix}$ is an eigenvector of the matrix $\begin{bmatrix} 4 & 1 & 2 \\ p & 2 & 1 \\ 14 & -4 & 10 \end{bmatrix}$ is _________.

asked Mar 28, 2018 in Linear Algebra by Milicevic3306 (15.8k points) | 13 views

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GATE ECE 2015 Set 1 | Question: 43
Two sequences $\begin{bmatrix}a, & b, & c \end{bmatrix}$ and $\begin{bmatrix}A, & B, & C \end{bmatrix}$ ... $\begin{bmatrix}p, & q, & r \end{bmatrix} = \begin{bmatrix} c, & b, & a \end{bmatrix}$

asked Mar 28, 2018 in Linear Algebra by Milicevic3306 (15.8k points) | 19 views

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GATE ECE 2014 Set 4 | Question: 46
The state transition matrix $\phi(t)$ of a system $\begin{bmatrix} x_1 \\ x_2 \end{bmatrix} = \begin{bmatrix} 0 & 1 \\ 0 & 0 \end{bmatrix} \begin{bmatrix} x_1 \\ x_2 \end{bmatrix}$ is $\begin{bmatrix} t & 1 \\ 1 & 0 \end{bmatrix} \\$ ... $\begin{bmatrix} 0 & 1 \\ 1 & t \end{bmatrix} \\$ $\begin{bmatrix} 1 & t \\ 0 & 1 \end{bmatrix}$

asked Mar 26, 2018 in Linear Algebra by Milicevic3306 (15.8k points) | 8 views

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GATE ECE 2014 Set 3 | Question: 27
Which one of the following statements is NOT true for a square matrix $A$? If $A$ is upper triangular, the eigenvalues of $A$ are the diagonal elements of it If $A$ is real symmetric, the eigenvalues of $A$ are always real and positive If $A$ ... $A$ are positive, all the eigenvalues of $A$ are also positive

asked Mar 26, 2018 in Linear Algebra by Milicevic3306 (15.8k points) | 17 views

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GATE ECE 2014 Set 3 | Question: 47
The state equation of a second-order linear system is given by $\dot{x}(t)=Ax(t), \:\:\:\:\:\:\:\:x(0)=x_{0}$ For $x_{0}= \begin{bmatrix} 1\\ -1 \end{bmatrix},$ $x(t)= \begin{bmatrix} e^{-t}\\ -e^{-t} \end{bmatrix},$ ... $\begin{bmatrix} 5e^{-t}-3e^{-2t}\\ -5e^{-t}+6e^{-2t} \end{bmatrix}$

asked Mar 26, 2018 in Linear Algebra by Milicevic3306 (15.8k points) | 18 views

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GATE ECE 2014 Set 2 | Question: 1
The determinant of matrix $A$ is $5$ and the determinant of matrix B is $40$. The determinant of matrix $AB$ is ________

asked Mar 26, 2018 in Linear Algebra by Milicevic3306 (15.8k points) | 19 views

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GATE ECE 2014 Set 2 | Question: 26
The system of linear equations $\begin{pmatrix} 2 & 1 & 3\\ 3&0 &1 \\ 1& 2 &5 \end{pmatrix} \begin{pmatrix} a\\ b\\ c \end{pmatrix} = \begin{pmatrix} 5\\ -4\\ 14 \end{pmatrix}$ has a unique solution infinitely many solutions no solution exactly two solutions

asked Mar 26, 2018 in Linear Algebra by Milicevic3306 (15.8k points) | 14 views

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GATE ECE 2014 Set 2 | Question: 28
The maximum value of the determinant among all $2 \times 2$ real symmetric matrices with trace $14$ is __________.

asked Mar 26, 2018 in Linear Algebra by Milicevic3306 (15.8k points) | 13 views

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21

GATE ECE 2014 Set 1 | Question: 1
For matrices of same dimension $M, N$ and scalar $c$, which one of these properties DOES NOT ALWAYS hold? $(M^{T})^{T} = M$ $(cM)^{T} = c(M)^{T}$ $(M+N)^{T} = M^{T} + N^{T}$ $MN = NM$

asked Mar 26, 2018 in Linear Algebra by Milicevic3306 (15.8k points) | 20 views

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GATE ECE 2014 Set 1 | Question: 4
A real $(4 \times 4)$ matrix $A$ satisfies the equation $A^{2} = I$, where $I$ is the $(4 \times 4)$ identity matrix. The positive eigen value of $A$ is ______.

asked Mar 26, 2018 in Linear Algebra by Milicevic3306 (15.8k points) | 24 views

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GATE ECE 2014 Set 1 | Question: 29
Consider the matrix ... $\alpha$ is a non-negative real number. The value of $\alpha$ for which $\text{det(P)} = 0$ is _______.

asked Mar 26, 2018 in Linear Algebra by Milicevic3306 (15.8k points) | 19 views

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GATE ECE 2013 | Question: 27
Let $A$ be an $m \times n$ matrix and $B$ an $n \times m$ matrix. It is given that determinant $(I_{m} + AB) =$ determinant $(I_{n} + BA),$ where $I_{k}$ is the $k \times k$ identity matrix. Using the above property, the determinant of the matrix given below ... $2$ $5$ $8$ $16$

asked Mar 26, 2018 in Linear Algebra by Milicevic3306 (15.8k points) | 16 views

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GATE ECE 2013 | Question: 19
The minimum eigenvalue of the following matrix is $\begin{bmatrix} 3& 5& 2\\5 &12 &7 \\2 &7 & 5\end{bmatrix}$ $0$ $1$ $2$ $3$

asked Mar 26, 2018 in Linear Algebra by Milicevic3306 (15.8k points) | 135 views

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GATE ECE 2012 | Question: 47
Given that $A=\begin{bmatrix} -5 &-3 \\ 2 &0\end{bmatrix}$ and $I=\begin{bmatrix} 1 & 0 \\ 0 &1\end{bmatrix}$, the value of $A^3$ is $15\:A+12\:I$ $19\:A+30\:I$ $17\:A+15\:I$ $17\:A+21\:I$

asked Mar 25, 2018 in Linear Algebra by Milicevic3306 (15.8k points) | 15 views

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GATE ECE 2018 | Question: 22
Consider matrix $A=\begin{bmatrix} k & 2k\\ k^{2}-k & k^{2} \end{bmatrix}$ and vector $x=\begin{bmatrix} x_{1}\\ x_{2} \end{bmatrix}.$ The number of distinct real value of $k$ for which the equation $Ax=0$ has infinitely many solutions is _________.

asked Feb 19, 2018 in Linear Algebra by gatecse (1.5k points) | 26 views

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GATE ECE 2018 | Question: 11
Let $\text{M}$ be a real $4\times 4$ matrix. Consider the following statements: $S1: M $ has $4$ linearly independent eigenvectors. $S2: M$ has $4$ distinct eigenvalues. $S3: M$ is non-singular (invertible). Which one among the following is TRUE? $S1$ implies $S2$ $S1$ implies $S3$ $S2$ implies $S1$ $S3$ implies $S2$

asked Feb 19, 2018 in Linear Algebra by gatecse (1.5k points) | 35 views

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GATE ECE 2017 Set 2 | Question: 1
The rank of the matrix $\begin{bmatrix} 1 & -1& 0& 0& 0& \\ 0& 0& 1& -1& 0& \\ 0& 1& -1& 0& 0& \\ -1& 0& 0& 0& 1& \\ 0& 0& 0& 1& -1& \end{bmatrix}$ is ________.

asked Nov 23, 2017 in Linear Algebra by admin (2.8k points) | 45 views

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GATE ECE 2017 Set 1 | Question: 1
Consider the 5 $\times$ 5 matrix $\begin{bmatrix} 1&2&3&4&5\\ 5&1 &2& 3 &4\\ 4&5&1&2&3\\ 3&4&5&1&2\\ 2&3&4&5&1 \end{bmatrix}$ It is given that A has only one real eigenvalue. Then the real eigenvalue of A is $-2.5$ $0$ $15$ $25$

asked Nov 17, 2017 in Linear Algebra by admin (2.8k points) | 135 views

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GATE ECE 2017 Set 1 | Question: 2
The rank of the matrix $\textbf{M} = \begin{bmatrix} 5&10&10 \\ 1 &0 &2 \\ 3&6&6 \end{bmatrix}$ is $0$ $1$ $2$ $3$

asked Nov 17, 2017 in Linear Algebra by admin (2.8k points) | 372 views