question_answer

Lf \[\Delta \]= , then A is equal to

A)   0                   

B)  1              

C)  2                                

D)  4

Correct Answer: D

Solution :

[d] \[\because \]\[\Delta \]= \[{{R}_{1}}\leftrightarrow {{R}_{1}}+{{R}_{2}}\] \[{{R}_{2}}\leftrightarrow {{R}_{2}}+{{R}_{3}}\] \[=\left[ \begin{align}   & 0\,\,\,0\,\,\,2 \\  & 2\,\,\,0\,\,\,0 \\  & 1\,\,\,1\,\,\,-1 \\ \end{align} \right]=4\] Hence, option [d] is correct.