NDA2019MathematicsQuadratic EquationActual
If A= x Z: x^3-1=0 and B= x Z: x^2+x+ .1=0 , where Z is set of complex numbers, then what is A B equal to ?
Options
- ANull set
- B-1+ 3 i 2 , -1- 3 i 2
- C-1+ 3 i 4 , -1- 3 i 4
- D1+ 3 i 2 , 1- 3 i 2
Correct answer
B. -1+ 3 i 2 , -1- 3 i 2
Step-by-step solution
Given, A = x z : x ^3-1=0 B= x z: x^2+x+1=0 The roots of x^3-1=0 are 1, w, w^2 The roots of x^2+x+1=0 are , ^2 A B= 1, , ^2 , ^2 aligned & = , ^2 & = -1+ 3 i 2 , -1- 3 i 2 aligned