Exact solutions for nonlinear partial differential equations via a fusion of classical methods and innovative approaches

This paper presents a new approach for finding exact solutions to certain classes of nonlinear partial differential equations (NLPDEs) by combining the variation of parameters method with classical techniques such as the method of characteristics. Our primary focus is on NLPDEs of the form \(u_{tt}+a(x,t)u_{xt}+b(t)u_{t}=\alpha (x,t)+ G(u)(u_{t}+a(x,t)u_{x})e^{-\int b(t)dt}\) $u_{\mathit{tt}}+a(x,t)u_{\mathit{xt}}+b(t)u_t=\alpha (x,t)+G(u)(u_t+a(x,t)u_x)e^{-\int b(t)dt}$ and \(u_{t}^{m}(u_{tt}+a(x,t)u_{xt})+b(t)u_{t}^{m+1}=e^{-(m+1)\int b(t)dt}(u_{t}+a(x,t)u_{x}) F(u,u_{t}e^{\int b(t)dt}).\) $u_t^m(u_{\mathit{tt}}+a(x,t)u_{\mathit{xt}})+b(t)u_t^{m+1}=e^{-(m+1)\int b(t)dt}(u_t+a(x,t)u_x)F(u,u_t{e}^{\int b(t)dt}).$ We provide numerical validation through several examples to ensure accuracy and reliability. Our approach enhances the applicability of analytical solution methods for a broader range of NLPDEs.