JEE Main & Advanced Sample Paper JEE Main Sample Paper-11

  • question_answer
    The solution of the equation 2z = | z | + 2i, where z if complex number, is                          

    A)  \[z=\frac{\sqrt{3}}{3}-i\]                             

    B)  \[z=\frac{\sqrt{3}}{3}+i\]

    C)  \[z=\frac{\sqrt{3}}{3}\pm i\]                     

    D)  None of these

    Correct Answer: B

    Solution :

     \[2(x+iy)=\sqrt{{{x}^{2}}+{{y}^{2}}}+2i\] \[2x=\sqrt{{{x}^{2}}+{{y}^{2}}}\]and\[2y=2\]i.e. \[y=1\] \[4{{x}^{2}}={{x}^{2}}+1\]i.e., \[3{{x}^{2}}=1\]i.e., \[x=\pm \frac{1}{\sqrt{3}}\] \[x=\frac{1}{\sqrt{3}}(\because x\ge 0)\therefore z=\frac{1}{\sqrt{3}}+i=\frac{\sqrt{3}}{3}+i\]


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