KCET · Maths · Probability
If \( \left|\begin{array}{ll}3 & x \\ x & 1\end{array}\right|=\left|\begin{array}{ll}3 & 2 \\ 4 & 1\end{array}\right| \) then \( x \) is equal to
- A \( 2 \)
- B \( 04 \)
- C \( 08 \)
- D \( \pm 2 \sqrt{2} \)
Answer & Solution
Correct Answer
(D) \( \pm 2 \sqrt{2} \)
Step-by-step Solution
Detailed explanation
Given that, \( \left|\begin{array}{cc}3 & x \\ x & 1\end{array}\right|=\left|\begin{array}{ll}3 & 2 \\ 4 & 1\end{array}\right| \)
\( 3-x^{2}=3-8 \)
\( \Rightarrow x^{2}=8 \Rightarrow x=\pm 2 \sqrt{2} \)
\( 3-x^{2}=3-8 \)
\( \Rightarrow x^{2}=8 \Rightarrow x=\pm 2 \sqrt{2} \)
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