Find the time dependence of the angle of deviation of a mathematical pendulum \(80 \mathrm{~cm}\) in length if at the initial moment the pendulum (a) was deviated through the angle \(3.0^{\circ}\) and then set free without push; (b) was in the equilibrium position and its lower end was imparted the horizontal velocity \(0.22 \mathrm{~m} / \mathrm{s}\) (c) was deviated through the angle \(3.0^{\circ}\) and its lower end was imparted the velocity \(0.22 \mathrm{~m} / \mathrm{s}\) directed toward the equilibrium position.