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OlympiadSuperchallengeOlympiad Number Theory

Olympiad Number Theory · Superchallenge problem

Points a=1a = 1, b=e2πi/3b = e^{2\pi i/3}, c=e4πi/3c = e^{4\pi i/3} lie on the unit circle. The foot of the perpendicular from p=0.5p = 0.5 (a real number) to chord bcbc is 12(b+c+p−bcpˉ)\dfrac12(b + c + p - bc\bar p). Compute the real part of that foot. Express your answer as a common fraction.