LFM Pure

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The system of equations $kx + y + z = 1$, $x + ky + z = k$ and $x + y + zk = k^2$ has no solution if $k$ is equal to:
(1) 0
(2) 1
(3) $-1$
(4) $-2$
jee-main 2021 Q72 View
If the following system of linear equations $2 x + y + z = 5$ $x - y + z = 3$ $x + y + a z = b$ has no solution, then :
(1) $a = - \frac { 1 } { 3 } , b \neq \frac { 7 } { 3 }$
(2) $a \neq \frac { 1 } { 3 } , b = \frac { 7 } { 3 }$
(3) $a \neq - \frac { 1 } { 3 } , b = \frac { 7 } { 3 }$
(4) $a = \frac { 1 } { 3 } , b \neq \frac { 7 } { 3 }$
jee-main 2021 Q86 View
If the system of equations $$\begin{aligned} & k x + y + 2 z = 1 \\ & 3 x - y - 2 z = 2 \\ & - 2 x - 2 y - 4 z = 3 \end{aligned}$$ has infinitely many solutions, then $k$ is equal to
Let the system of linear equations $x + y + a z = 2$ $3 x + y + z = 4$ $x + 2 z = 1$ have a unique solution $\left( x ^ { * } , y ^ { * } , z ^ { * } \right)$. If $\left( \left( a , x ^ { * } \right) , \left( y ^ { * } , \alpha \right) \right.$ and $\left( x ^ { * } , - y ^ { * } \right)$ are collinear points, then the sum of absolute values of all possible values of $\alpha$ is:
(1) 4
(2) 3
(3) 2
(4) 1
jee-main 2022 Q68 View
If the system of linear equations $8 x + y + 4 z = - 2$ $x + y + z = 0$ $\lambda x - 3 y = \mu$ has infinitely many solutions, then the distance of the point $\left( \lambda , \mu , - \frac { 1 } { 2 } \right)$ from the plane $8 x + y + 4 z + 2 = 0$ is:
(1) $3 \sqrt { 5 }$
(2) 4
(3) $\frac { 26 } { 9 }$
(4) $\frac { 10 } { 3 }$
If the system of equations $\alpha x + y + z = 5 , x + 2 y + 3 z = 4 , x + 3 y + 5 z = \beta$ has infinitely many solutions, then the ordered pair $( \alpha , \beta )$ is equal to
(1) $( 1 , - 3 )$
(2) $( - 1,3 )$
(3) $( 1,3 )$
(4) $( - 1 , - 3 )$
If the system of linear equations $2x + 3y - z = -2$ $x + y + z = 4$ $x - y + |\lambda|z = 4\lambda - 4$ where $\lambda \in \mathbb{R}$, has no solution, then
(1) $\lambda = 7$
(2) $\lambda = -7$
(3) $\lambda = 8$
(4) $\lambda^2 = 1$
If the system of equations $x + y + z = 6$ $2x + 5y + \alpha z = \beta$ $x + 2y + 3z = 14$ has infinitely many solutions, then $\alpha + \beta$ is equal to
(1) 8
(2) 36
(3) 44
(4) 48
jee-main 2022 Q70 View
The ordered pair $( a , b )$, for which the system of linear equations $3 x - 2 y + z = b$ $5 x - 8 y + 9 z = 3$ $2 x + y + a z = - 1$ has no solution, is
(1) $\left( 3 , \frac { 1 } { 3 } \right)$
(2) $\left( - 3 , \frac { 1 } { 3 } \right)$
(3) $\left( - 3 , - \frac { 1 } { 3 } \right)$
(4) $\left( 3 , - \frac { 1 } { 3 } \right)$
The system of equations $-kx + 3y - 14z = 25$ $-15x + 4y - kz = 3$ $-4x + y + 3z = 4$ is consistent for all $k$ in the set
(1) $R$
(2) $R - \{-11, 13\}$
(3) $R - \{-13\}$
(4) $R - \{-11, 11\}$
If the system of linear equations $2 x + y - z = 7$ $x - 3 y + 2 z = 1$ $x + 4 y + \delta z = k$, where $\delta , k \in R$ has infinitely many solutions, then $\delta + k$ is equal to
(1) $- 3$
(2) 3
(3) 6
(4) 9
Let $N$ denote the number that turns up when a fair die is rolled. If the probability that the system of equations $x + y + z = 1$, $2 x + N y + 2 z = 2$, $3 x + 3 y + N z = 3$ has unique solution is $\frac { k } { 6 }$, then the sum of value of $k$ and all possible values of $N$ is
(1) 18
(2) 19
(3) 20
(4) 21
jee-main 2023 Q69 View
For the system of linear equations $x + y + z = 6$ $\alpha x + \beta y + 7z = 3$ $x + 2y + 3z = 14$ which of the following is NOT true?
(1) If $\alpha = \beta = 7$, then the system has no solution
(2) If $\alpha = \beta$ and $\alpha \neq 7$ then the system has a unique solution.
(3) There is a unique point $(\alpha, \beta)$ on the line $x + 2y + 18 = 0$ for which the system has infinitely many solutions
(4) For every point $(\alpha, \beta) \neq (7,7)$ on the line $x - 2y + 7 = 0$, the system has infinitely many solutions.
jee-main 2023 Q69 View
For the system of linear equations $$2x - y + 3z = 5$$ $$3x + 2y - z = 7$$ $$4x + 5y + \alpha z = \beta$$ which of the following is NOT correct?
(1) The system has infinitely many solutions for $\alpha = -5$ and $\beta = 9$
(2) The system has infinitely many solutions for $\alpha = -6$ and $\beta = 9$
(3) The system is inconsistent for $\alpha = -5$ and $\beta = 8$
(4) The system has a unique solution for $\alpha \neq -5$ and $\beta = 8$
jee-main 2023 Q71 View
If the system of equations $$\begin{aligned} & 2 x + y - z = 5 \\ & 2 x - 5 y + \lambda z = \mu \\ & x + 2 y - 5 z = 7 \end{aligned}$$ has infinitely many solutions, then $( \lambda + \mu ) ^ { 2 } + ( \lambda - \mu ) ^ { 2 }$ is equal to
(1) 904
(2) 916
(3) 912
(4) 920
jee-main 2023 Q75 View
Let $S _ { 1 }$ and $S _ { 2 }$ be respectively the sets of all $a \in R - \{ 0 \}$ for which the system of linear equations $a x + 2 a y - 3 a z = 1$ $( 2 a + 1 ) x + ( 2 a + 3 ) y + ( a + 1 ) z = 2$ $( 3 a + 5 ) x + ( a + 5 ) y + ( a + 2 ) z = 3$ has unique solution and infinitely many solutions. Then
(1) $\mathrm { n } \left( S _ { 1 } \right) = 2$ and $S _ { 2 }$ is an infinite set
(2) $S _ { 1 }$ is an infinite set and $n \left( S _ { 2 } \right) = 2$
(3) $S _ { 1 } = \phi$ and $S _ { 2 } = \mathbb { R } - \{ 0 \}$
(4) $S _ { 1 } = \mathbb { R } - \{ 0 \}$ and $S _ { 2 } = \phi$
jee-main 2023 Q75 View
Consider the following system of questions
$$\begin{aligned} & \alpha x + 2 y + z = 1 \\ & 2 \alpha x + 3 y + z = 1 \\ & 3 x + \alpha y + 2 z = \beta \end{aligned}$$
For some $\alpha , \beta \in \mathbb { R }$. Then which of the following is NOT correct.
(1) It has no solution if $\alpha = - 1$ and $\beta \neq 2$
(2) It has no solution for $\alpha = - 1$ and for all $\beta \in \mathbb { R }$
(3) It has no solution for $\alpha = 3$ and for all $\beta \neq 2$
(4) It has a solution for all $\alpha \neq - 1$ and $\beta = 2$
jee-main 2023 Q75 View
For $\alpha, \beta \in \mathbb{R}$, suppose the system of linear equations $x - y + z = 5$ $2x + 2y + \alpha z = 8$ $3x - y + 4z = \beta$ has infinitely many solutions. Then $\alpha$ and $\beta$ are the roots of
(1) $x^{2} - 10x + 16 = 0$
(2) $x^{2} + 18x + 56 = 0$
(3) $x^{2} - 18x + 56 = 0$
(4) $x^{2} + 14x + 24 = 0$
For the system of equations $x + y + z = 6$ $x + 2y + \alpha z = 10$ $x + 3y + 5z = \beta$, which one of the following is NOT true?
(1) System has no solution for $\alpha = 3, \beta = 24$
(2) System has a unique solution for $\alpha = -3, \beta = 14$
(3) System has infinitely many solutions for $\alpha = 3, \beta = 14$
(4) System has a unique solution for $\alpha = 3, \beta = 14$
jee-main 2024 Q69 View
Consider the system of linear equations $x + y + z = 5$, $x + 2y + \lambda^2 z = 9$ and $x + 3y + \lambda z = \mu$, where $\lambda, \mu \in R$. Then, which of the following statement is NOT correct?
(1) System has infinite number of solution if $\lambda = 1$
(2) System is inconsistent if $\lambda = 1$ and $\mu \neq 13$ and $\mu = 13$
(3) System has unique solution if $\lambda \neq 1$ and $\mu \neq 13$
(4) System is consistent if $\lambda \neq 1$ and $\mu = 13$
jee-main 2024 Q70 View
The values of $m , n$, for which the system of equations \begin{align*} x + y + z &= 4, 2x + 5y + 5z &= 17, x + 2y + \mathrm{m}z &= \mathrm{n} \end{align*} has infinitely many solutions, satisfy the equation:
(1) $m ^ { 2 } + n ^ { 2 } - m n = 39$
(2) $m ^ { 2 } + n ^ { 2 } - m - n = 46$
(3) $m ^ { 2 } + n ^ { 2 } + m + n = 64$
(4) $m ^ { 2 } + n ^ { 2 } + m n = 68$
jee-main 2024 Q70 View
If the system of equations $x + 4 y - z = \lambda , 7 x + 9 y + \mu z = - 3,5 x + y + 2 z = - 1$ has infinitely many solutions, then $( 2 \mu + 3 \lambda )$ is equal to : (1) 3 (2) - 3 (3) - 2 (4) 2
Let the system of equations $x + 2y + 3z = 5$, $2x + 3y + z = 9$, $4x + 3y + \lambda z = \mu$ have infinite number of solutions. Then $\lambda + 2\mu$ is equal to:
(1) 28
(2) 17
(3) 22
(4) 15
Consider the system of linear equation $x + y + z = 4 \mu , x + 2 y + 2 \lambda z = 10 \mu , x + 3 y + 4 \lambda ^ { 2 } z = \mu ^ { 2 } + 15$, where $\lambda , \mu \in \mathrm { R }$. Which one of the following statements is NOT correct?
(1) The system has unique solution if $\lambda \neq \frac { 1 } { 2 }$ and $\mu \neq 1$
(2) The system is inconsistent if $\lambda = \frac { 1 } { 2 }$ and $\mu \neq 1, 15$
(3) The system has infinite number of solutions if $\lambda = \frac { 1 } { 2 }$ and $\mu = 15$
(4) The system is consistent if $\lambda \neq \frac { 1 } { 2 }$
If $( a , b )$ be the orthocentre of the triangle whose vertices are $( 1,2 ) , ( 2,3 )$ and $( 3,1 )$, and $I _ { 1 } = \int _ { \mathrm { a } } ^ { \mathrm { b } } \mathrm { x } \sin \left( 4 \mathrm { x } - \mathrm { x } ^ { 2 } \right) \mathrm { dx } , \mathrm { I } _ { 2 } = \int _ { \mathrm { a } } ^ { \mathrm { b } } \sin \left( 4 \mathrm { x } - \mathrm { x } ^ { 2 } \right) \mathrm { dx }$, then $36 \frac { I _ { 1 } } { I _ { 2 } }$ is equal to:
(1) 72
(2) 88
(3) 80
(4) 66