Number of real values λ , such that system of linear equations 2 x-3 y+5 z=9 ; x+3 y-z

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3 and 4 .Determinants and Matrices

hard

The number of real values $\lambda$, such that the system of linear equations $2 x-3 y+5 z=9$ ; $x+3 y-z=-18$ ; $3 x-y+\left(\lambda^{2}-1 \lambda \mid\right) z=16$ has no solution, is :-

$0$

$1$

$2$

$4$

(JEE MAIN-2022)

Solution

$\Delta=\left|\begin{array}{ccc}2 & -3 & 5 \\ 1 & 3 & -1 \\ 3 & -1 & \lambda^{2}-|\lambda|\end{array}\right|=2\left(3 \lambda^{2}-3|\lambda|-1\right)$

$+3\left(\lambda^{2}-|\lambda|+3\right)$

$+5(-1-9)$

$=9 \lambda^{2}-9|\lambda|-43$

$=9|\lambda|^{2}-9|\lambda|-43$

$\Delta=0$ for 2 values of $|\lambda|$ out of which one is $-ve$ and other is $+ve$

So,$2$ values of $\lambda$ satisfy the system of equations to obtain no solution

Standard 12

Mathematics

Let the system of linear equations $x+y+k z=2$ ; $2 x+3 y-z=1$ ; $3 x+4 y+2 z=k$ , have infinitely many solutions. Then the system $( k +1) x +(2 k -1) y =7$ ; $(2 k +1) x +( k +5) y =10 \text { has : }$

hard

(JEE MAIN-2023)

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hard

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hard

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hard

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easy

The number of real values $\lambda$, such that the system of linear equations $2 x-3 y+5 z=9$ ; $x+3 y-z=-18$ ; $3 x-y+\left(\lambda^{2}-1 \lambda \mid\right) z=16$ has no solution, is :-

Solution

Similar Questions

Let the system of linear equations $x+y+k z=2$ ; $2 x+3 y-z=1$ ; $3 x+4 y+2 z=k$ , have infinitely many solutions. Then the system $( k +1) x +(2 k -1) y =7$ ; $(2 k +1) x +( k +5) y =10 \text { has : }$

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