“…In many fields, the optimal control problems play a significant role in life. Different examples of the applications of such problems are presented in medicine [1], aircraft industry [2], electric power production [3], economic growth [4], and many other fields. All these applications pushed many investigators to a higher level of interest in studying the optimal control problem for nonlinear ordinary differential equations [5], for different types of linear partial differential equations, including the hyperbolic, parabolic and elliptic [6][7][8], or for couple nonlinear partial differential equations of these three types [9][10][11].…”