COMEDK2017MathematicsComplex Number
If the cube roots of unity are 1, , ² , then the roots of the equation (x-1)³+8=0 are
Options
- A-1,-1,-1
- B-1,-1+2 .-1-2 ²
- C-1,1+2 , 1+2 ²
- D-1,1-2 w i -2 w ²
Correct answer
D. -1,1-2 w i -2 w ²
Step-by-step solution
We have, aligned & &(x-1)³ &=-8=(-2)³ & & x-1 &=-2,-2 ,-2 ² & & x &=-1,1-2 , 1-2 ² aligned