Lag1989 task №7.4

The material point vibrates along the axis according to the law x = A · sinωt, where ω = 1.57 s⁻ˡ. The amplitude of the point velocity Av = 9.42 · 10⁻²m / s. Find for the moments of time t₁ = 0; t₂ = T / 8 and t₃ = T / 4 values of the x-coordinate, velocity V and acceleration a of the point. Determine the average values of speed and acceleration for the time intervals τ₁ = t₂-t₁ and τ₂ = t₃-t₂.