RAJASTHAN ­ PET Rajasthan PET Solved Paper-2006

  • question_answer
    If\[\alpha \]and\[\beta \]are two complex numbers and\[|P|=1,\]then the value of\[\left| \frac{\beta -\alpha }{1-\overline{\alpha }\beta } \right|\]is

    A)  0               

    B)  1

    C)  1               

    D)  2

    Correct Answer: C

    Solution :

     Given, \[|\beta |=1\Rightarrow |\beta {{|}^{2}}=1\Rightarrow \beta \overline{\beta }=1\] \[\therefore \] \[\left| \frac{\beta -\alpha }{1-\alpha \overline{\beta }} \right|=\left| \frac{\beta -\alpha }{\beta \overline{\beta }-\overline{\alpha }\beta } \right|\] \[=\left| \frac{\beta -\alpha }{\beta (\overline{\beta }-\overline{\alpha })} \right|\] \[=\frac{1}{|\beta |}\left| \frac{\beta -\alpha }{\overline{\beta }-\overline{\alpha }} \right|\] \[=\frac{1}{|\beta |}=1\] \[[\because |z|=|\overline{z}|]\]


You need to login to perform this action.
You will be redirected in 3 sec spinner