“…Hyperbolic partial differential equations with both constant/variable coefficients are of common occurrence in many branches of physics and several other areas of science and engineering, e.g., electromagnetic, electrodynamics, thermodynamics, hydrodynamics, elasticity, fluid dynamics, wave propagation, materials science and biological systems [1][2][3][4][5][6][7][8][9][10][11][12]. In numerical techniques for solving these equations, the problem of stability in various functional spaces has received a great deal of importance and attention (see [13][14][15][16][17][18][19][20][21]).…”