Question
      
        If the roots of $${a_1}{x^2} + {b_1}x + {c_1} = 0$$     are $${\alpha _1},{\beta _1},$$  and those of $${a_2}{x^2} + {b_2}x + {c_2} = 0$$     are $${\alpha _2},{\beta _2}$$  such that $${\alpha _1}{\alpha _2} = {\beta _1}{\beta _2} = 1$$    then      
       A.
        $$\frac{{{a_1}}}{{{a_2}}} = \frac{{{b_1}}}{{{b_2}}} = \frac{{{c_1}}}{{{c_2}}}$$              
       B.
        $$\frac{{{a_1}}}{{{c_2}}} = \frac{{{b_1}}}{{{b_2}}} = \frac{{{c_1}}}{{{a_2}}}$$                 
              
       C.
        $${a_1}{a_2} = {b_1}{b_2} = {c_1}{c_2}$$              
       D.
        None of these              
            
                Answer :  
        $$\frac{{{a_1}}}{{{c_2}}} = \frac{{{b_1}}}{{{b_2}}} = \frac{{{c_1}}}{{{a_2}}}$$      
             Solution :
        Roots of the second equation are reciprocal of those of the first.
$$\therefore \,\,{c_1}{x^2} + {b_1}x + {a_1} = 0\,\,{\text{and }}{a_2}{x^2} + {b_2}x + {c_2} = 0$$          have both roots common.