AP EAMCET202021 Sep 2020Morning ShiftMathematicsComplex NumberActual
((-i+ 3 )³⁰⁰+(-i- 3 )³⁰⁰= )
Options
- A(2³⁰⁰ )
- B(2³⁰¹ )
- C(2¹⁰⁰ )
- D(-2³⁰⁰ )
Correct answer
B. (2³⁰¹ )
Step-by-step solution
( aligned &(-i+ 3 )³⁰⁰+(-i- 3 )³⁰⁰=(i- 3 )³⁰⁰ +(-i- 3 )³⁰⁰ &= i³⁰⁰(1+i 3 )³⁰⁰+i³⁰⁰(-1+i 3 )³⁰⁰ &= (-2 w^2 )³⁰⁰+(2 w)³⁰⁰ where w is cube root of unity &= 2³⁰⁰ [ (w^2 )³⁰⁰+w³⁰⁰ ]=2³⁰⁰ 2=2³⁰¹ aligned ) Hence, option (b) is correct.