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MathsMediumNumerical2021 · 26 Aug Shift 2

Q82.The least positive integer n such that , i = √−1, is a positive integer, is ______. (1−i)n−2

What This Question Tests

This question requires simplifying a complex expression involving powers of (2i) and (1-i) and determining the least positive integer 'n' for which the result is a positive integer, utilizing properties of 'i' and potentially polar form.

Concepts Tested

Powers of iPolar form of complex numbersDe Moivre's Theorem

Formulas Used

i² = -1, i³ = -i, i⁴ = 1

(1-i) = √2 e^(-iπ/4)

(a+bi)^n

(x+iy) / (a+ib)

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