J & K CET Engineering J and K - CET Engineering Solved Paper-2004

  • question_answer
    The complex numbers having positive argument and satisfying \[|2-3i|\,\,<\] is

    A)  \[\frac{12}{5}+\frac{16}{5}\,i\]

    B)  \[\frac{4}{5}+\frac{6}{5}\,i\]

    C)  \[\frac{6}{5}-\frac{5}{2}\,i\]

    D)  None of these

    Correct Answer: A

    Solution :

    Let  \[z=\frac{12}{5}+\frac{16}{5}t\] \[\therefore \] \[\arg \,(z)=\frac{16}{12}=\frac{4}{3}>0\] and \[|z|=\sqrt{{{\left( \frac{12}{5} \right)}^{2}}+{{\left( \frac{16}{5} \right)}^{2}}}\] \[=\frac{1}{5}\sqrt{144+256}=\frac{29}{5}=4\] Now, \[|2-3i|=\sqrt{4+9}=\sqrt{13}\] \[\therefore \] \[|2-3i|<|z|\] Hence, option [a] is correct.


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