2. Solved Papers
  3. CEE Kerala Engineering

CEE Kerala Engineering CEE Kerala Engineering Solved Paper-2010

  • question_answer
    If\[{{(x+iy)}^{1/3}}=2+3i,\]then\[3x+2y\]is equal to

    A)  \[-20\]                                

    B)  \[-60\]

    C)  \[-120\]              

    D)         60

    E)  \[156\]

    Correct Answer: C

    Solution :

    Given, \[{{(x+iy)}^{1/3}}=2+3i\] \[\Rightarrow \]               \[x+iy={{(2+3i)}^{3}}\] \[\Rightarrow \]               \[x+iy=-46+9i\] \[\Rightarrow \]               \[x=-46,y=9\] \[\therefore \]  \[3x+2y=3\times (-46)+2\times 9\]                                 \[=-138+18=-120\]


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