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Manipal MET2021MathematicsComplex Number

If is a cube root of unity, then (1+ - ^2 ) (1- + ^2 ) is

Options

  1. A1
  2. B0
  3. C2
  4. D4

Correct answer

D. 4

Step-by-step solution

If is a cube root of unity, then aligned & 1+ + ^2=0 and ^3=1 . & aligned (1+ - ^2 ) & (1- + ^2 ) & = (- ^2- ^2 )(- - ) & =2 ^2 2 =4 aligned aligned

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