NTA Abhyas JEE Main2020MathematicsComplex NumberPractice
Let ω   ω ≠ 1 is a cube root of unity, such that 1 + ω 2 8 = a + b ω where a , b ∈ R , then a + b is equal to
Options
- A1
- B3
- C0
- D2
Correct answer
D. 2
Step-by-step solution
- ω 8 = a + b ω ⇒ ω 2 = a + b ω … … … i ⇒ - 1 2 - i 3 2 = a + b - 1 2 + i 3 2 Comparing real and imaginary parts a = - 1 , b = - 1 ⇒ a + b = 2