In the previous question, the angular frequency of the simple harmonic motion is ω. The coefficient of friction between the coin and the platform is μ. The amplitude of oscillation is gradually increased. The coin will begin to slip on the platform for the first time (i) at the extreme positions of oscillations (ii) at the mean position (iii) for an amplitude of μg/ω^2 (iv) for an amplitude of g/μω^2