NTA Abhyas JEE Main2020MathematicsComplex NumberPractice
If i 2 = - 1 and 1 + i 2 n = 1 - i 2 m = 1 ,   ∀ n , m ∈ N , then the minimum value of n + m is equal to
Correct answer
16
Step-by-step solution
Here, 1 + i 2 = e i π 4 and 1 - i 2 = e - i π 4 Now, e i π 4 n = e - i π 4 m = 1 ⇒ n π 4 = - m π 4 = 2 k π ,   ∀ k ∈ Z Hence, n = 8 k and m = - 8 k So n m i n = m m i n = 8 i.e. n + m = 16