The real part of complex number z= 2a+i\left ( 7-a \right ) when z becomes purely real will be  \left ( a\: \epsilon\: R \right )

  • Option 1)

    14

  • Option 2)

    -14

  • Option 3)

    16

  • Option 4)

    -16

 

Answers (1)
V Vakul

z will be purely real if 7-a=0

i.e. a=7

So, real part of z becomes 2x7=14

\therefore Option A

 

Purely Real Complex Number -

z=x+iy, x\epsilon R, \boldsymbol{y=0}

& i2=-1

- wherein

Real part of z = Re (z) = x & Imaginary part of z = Im (z) = y

 

 

 


Option 1)

14

This is correct

Option 2)

-14

This is incorrect

Option 3)

16

This is incorrect

Option 4)

-16

This is incorrect

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