NTA Abhyas JEE Main2020MathematicsComplex NumberPractice
For a complex number Z , if one root of the equation Z 2 - a Z + a = 0 is 1 + i and its other root is α , then the value of a α 4 is equal to
Options
- A4
- B- 1 2
- C2
- D- 2
Correct answer
B. - 1 2
Step-by-step solution
α + 1 + i = a α 1 + i = a α + α i = α + 1 + i ⇒ α = 1 + i i = 1 - i a = 1 - i + 1 + i = 2 α 4 = α 2 2 = 1 + - 1 - 2 i 2 = - 2 i 2 = 4 i 2 = - 4