A weight is attached to a spring suspended vertically from a ceiling. When a driving force is applied to the system, the weight moves vertically from its equilibrium position, and this motion is modeled byy=13sin2t+14cos2twhere yis the distancefrom equilibrium (in feet) and tis the time (in seconds).a. Usethe identity a∙sinBθ+b∙cosBθ=a!+b!∙sinBt+Cwhere C=arctan!!,a>0,to write the model in the form y=a!+b!∙sinBt+C. b.State the amplitude of the oscillations of the weight