NDA2023MathematicsComplex NumberActual
If is a non-real cube root of 1 , then what is the value of | 1- + ^2 | ?
Options
- A3
- B2
- C1
- D4 3
Correct answer
A. 3
Step-by-step solution
| 1-w w+w^2 |= | 1-w -1 |=|w-1| [ 1+w+w^2=0 ]= | -1+ 3 i 2 -1 |= | -1+ 3 i-2 2 |= | -3 2 + 3 2 i |= ( -3 2 )^2+ ( 3 2 )^2 = 9 4 + 3 4 = 3