Continuous time dynamical systems : state estimation and optimal control with orthogonal functions This book presents the developments in problems of state estimation and optimal control of continuous time dynamical systems using orthogonal functions since 1975. It deals with both full and reduced order state estimation and problems of linear time invariant systems. It also addresses optimal control problems of varieties of continuous time systems such as linear and nonlinear systems time invariant and time varying systems as well as delay free and time delay systems. Content focuses on development of recursive algorithms for studying state estimation and optimal control problems