Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Determinants

Question:

If \(x,y,z\) are positive number \(\left|\begin{array}{lll}1& \log_{x}y & \log_{x}z\\ \log_{y}x& 1 & \log_{y}z\\ \log_{z}x & \log_{z}y&1\end{array}\right|\) is equal to 

Options:

\(0\)

\(3\)

\(\log_{e}xyz\)

\(\log_{e}(x+y+z)\)

Correct Answer:

\(0\)

Explanation:

\(\left|\begin{array}{lll}1& \log_{x}y & \log_{x}z\\ \log_{y}x& 1 & \log_{y}z\\ \log_{z}x & \log_{z}y&1\end{array}\right|\)

$=\frac{1}{\log_{x}\log_{y}\log_{z}}\begin{vmatrix}\log_{x}&\log_{y}&\log_{z}\\\log_{x}&\log_{y}&\log_{z}\\\log_{x}&\log_{y}&\log_{z}\end{vmatrix}$

$=\frac{\log_{x}\log_{y}\log_{z}}{\log_{x}\log_{y}\log_{z}}\begin{vmatrix}1&1&1\\1&1&1\\1&1&1\end{vmatrix}$

$=0$