Let for some real numbers α and β , a = α - i β . If the system of equations 4 i x + 1 +…

Let for some real numbers α and β,a=α-iβ. If the system of equations 4ix+1+iy=0 and 8cos2π3+isin2π3x+a¯y=0 has more than one solution then αβ is equal to
  1. 2-3
  2. 2+3
  3. -2+3
  4. -2-3

Solution

The given system of equations has more than one solution, then it must have infinitely many solutions.

So, 4i8cos2π3+isin2π3=1+iα+iβ    a=α-iβa=α+iβ

4i8-12+i32=1+iα+iβ

αi-β=-1-i+3i-3

-β+αi=-1-3+-1+3i

α=-1+3 & -β=-1-3

αβ=-1+31+3=-1+31+3×1-31-3

=-1-321-3=1+3-232=2-3  

Asked in: JEE Main 2022 (27 Jun Shift 2)

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