Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Determinants

Question:

The value of \(x\) for which \(\left|\begin{array}{ll}3&x\\ x&1\end{array}\right|=\left|\begin{array}{ll}3&2\\ 4&1\end{array}\right|\) is 

Options:

\(2\)

\(3\)

\(±2\sqrt{2}\)

\(0\)

Correct Answer:

\(±2\sqrt{2}\)

Explanation:

\(\left|\begin{array}{ll}3&x\\ x&1\end{array}\right|=\left|\begin{array}{ll}3&2\\ 4&1\end{array}\right|⇒3-x^2=3-8\)

$⇒x^2=8$

$⇒x=±2\sqrt{2}$