If the system of equations $x+ ay =0, az+ y = 0 $ and $ ax+z = 0 $ has infinite solutions, then the value of a, is
Answer & explanation
Correct answer: option 2
The correct answer is option (2) : -1
The given system of equations will have infinitely many solutions, if
$\begin{vmatrix} 1 & a & 0 \\ 0 & 1 & a\\ a & 0 & 1\end{vmatrix} =0$
$⇒1+a^3 =0 ⇒a=-1 $