Q53 / 160 · TS EAMCET 2021 (04 Aug Shift 1) · Mathematics

If α, β, γ are the roots of x3-x+1=0, then 1+α1-α+1+β1-β+1+γ1-γ=

  • Correct answer
    A
    1
  • B
    0
  • C
    2
  • D
    -2

Solution

The given equation  x3-x+1=0

We know that If α,β,γ are the roots of the equation α+β+γ=-ba,αβ+βγ+γα=ca,αβγ=-da

∴α+β+γ=0, αβγ=-1, αβ+βγ+γα=-1

Given 1+α1-α+1+β1-β+1+γ1-γ=(1+α)(1−β)(1−γ)+(1−α)(1+β)(1−γ)+(1−α)(1−β)(1+γ) ​  (1-α)(1-β)(1-γ)

=3−(α+β+γ)−(αβ+βγ+γα)+3(αβγ)1-(α+β+γ)−(αβ+βγ+γα)+(αβγ)

=3-0-(-1)+3(-1)1-0-(-1)-1

=3+1-31+1-1

=1

 

Hence, the correct answer is option: 'A'.

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