COMEDK2012MathematicsComplex Number
If is a cube root of unity, then the value of determinant | array ccc 1+ & ² & ²+ & - & ² 1+ ² & & ² array | is equal to
Options
- A1+
- B1-
- C0
- D²
Correct answer
B. 1-
Step-by-step solution
We have, | array ccc 1+ & ² & ²+ & - & ² 1+ ² & & ² array | = | array ccc 1+ + ² & ² & ² & - & ² 1+ + ² & & ² array | (C₁ C₁+C₂ ) aligned &= | array ccc 0 & ² & ² & - & ² 0 & & ² array | & .=0- ² ( ⁴-0 )+ ( )³-0 ) &=- ⁶+ ⁴ aligned =-1+ [ ³=1 ]= -1