Let Z 1 , Z 2 , Z 3 be three non zero complex numbers such that a = Z 1 , b = Z 2 , c = Z 3 . if the…

Let Z1,Z2,Z3 be three non zero complex numbers such that a=Z1,b=Z2,c=Z3. if the determinant abcbcacab=0, then
  1. Z1=Z2=Z3=abc
  2. Z1+Z2+Z3=0
  3. Z1+Z2+Z3=abc
  4. Z1-Z2=Z2-Z3

Solution

Let Z1,Z2,Z3 be three non zero complex numbers such that a=Z1,b=Z2,c=Z3.

Given,  abcbcacab=0

abc-a2-bb2-ac+cab-c2=0

abc-a3-b3+abc+abc-c3=0

3abc-a3-b3-c3=0

a3+b3+c3-3abc=0

We know that:a3+b3+c3-3abc=a+b+ca2+b2+c2-ab-bc-ca

a+b+ca2+b2+c2-ab-bc-ca=0

Multiplying and dividing by 2

12a+b+c2a2+2b2+2c2-2ab-2bc-2ca=0

12a+b+ca-b2+b-c2+c-a2=0

a+b+c=0

Hence, z1+z2+z3=0

Asked in: AP EAMCET 2021 (20 Aug Shift 2)

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