কোনটি নির্ণায়ক?

$\left(\begin{array}{ll}a_{1} & b_{1} \\a_{2} & b_{2}\end{array}\right)$

$\left|\begin{array}{lll}a_{2} & b_{1} & c_{1} \\a_{2} & b_{2} & c_{2}\end{array}\right|$

$|| \begin{array}{ll}a_{1} & b_{1} \\a_{2} & b_{2}\end{array}||$

$\left|\begin{array}{ll}a_{1} & b_{1} \\a_{2} & b_{2}\end{array}\right|$