question_answer

The lines \[{{a}_{1}}x+{{b}_{1}}y+{{c}_{1}}=0\]and \[{{a}_{2}}x+{{b}_{2}}y+{{c}_{2}}=0\] are perpendicular to each other, if                        [MP PET 1996]

A)            \[{{a}_{1}}{{b}_{2}}-{{b}_{1}}{{a}_{2}}=0\]                

B)            \[{{a}_{1}}{{a}_{2}}+{{b}_{1}}{{b}_{2}}=0\]

C)            \[a_{1}^{2}{{b}_{2}}+b_{1}^{2}{{a}_{2}}=0\]         

D)            \[{{a}_{1}}{{b}_{1}}+{{a}_{2}}{{b}_{2}}=0\]