A point performs damped oscillations with frequency ω and damping coefficient β according to the law (4.1b). Find the initial amplitude a0 and the initial phase α if at the moment t = 0 the displacement of the point and its velocity projection are equal to
(a) x (0) = 0 and vx (0) =
(b) x (0) = x0 and vx (0) = 0.