Ask Questions, Get Answers

Want to ask us a question? Click here
Browse Questions
0 votes

Let $z=\begin{vmatrix}1&2+3i&4+5i\\2-3i&6&7+8i\\4-5i&7-8i&-9\end{vmatrix}$,then

$\begin{array}{1 1}(A)z \;is\;purely\;real \\ (B) z \;is\;purely\;imaginary \\ (C) z=0 \\(D) none\;of\;these \end{array}$

Can you answer this question?

1 Answer

0 votes
Conjugate of z equals determinant obtained by taking conjugate of each of its element
$\overline {z}=\begin{vmatrix}1&2+3i&4+5i\\2-3i&6&7+8i\\4-5i&7-8i&-9\end{vmatrix}=z$
$\Rightarrow z$ is purely real.
Hence (A) is the correct answer.
answered Apr 9, 2014 by sreemathi.v

Related questions

Ask Question
student study plans
JEE MAIN, CBSE, NEET Mobile and Tablet App
The ultimate mobile app to help you crack your examinations
Get the Android App