Target Exam

CUET

Subject

Section B2

Chapter

Algebra

Question:

The integral value of k for which the system of linear equations $kx + y + 2z = 0, ky=x-3z$ and $2x + y + kz = 0$ has a non-zero solution is

Options:

2

1

3

5

Correct Answer:

2

Explanation:

The correct answer is Option (1) → 2 **

Coefficient matrix:

$\begin{vmatrix}k & 1 & 2\\ -1 & k & 3\\ 2 & 1 & k\end{vmatrix}=0$

Determinant:

$k^3-6k+4=0$

Factorising: $(k-2)(k^2+2k-2)=0$ ⇒ $k=2,\ -1\pm\sqrt{3}$

Integral value of $k$ is 2.