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