Infinite body,rectangular coordinate, steady 1-D Helmholtz.

X00 Infinite body, - $\infty$ < x < $\infty$.

$$\left\vert\vphantom{ \,x^{\prime }}\right. \prime \left.\vphantom{ \,x^{\prime }}\right. \left\{\vphantom{ \begin{array}{cc} e^{-mx^{\prime }}e^{mx}/(2m)... ...\ e^{mx^{\prime }}e^{-mx}/(2m) & \text{for }x>x^{\prime } \end{array} }\right. \begin{array}{cc} e^{-mx^{\prime }}e^{mx}/(2m) & \text{for }x<x^{\prime } \\ e^{mx^{\prime }}e^{-mx}/(2m) & \text{for }x>x^{\prime } \end{array} \left.\vphantom{ \begin{array}{cc} e^{-mx^{\prime }}e^{mx}/(2m) ... ...\ e^{mx^{\prime }}e^{-mx}/(2m) & \text{for }x>x^{\prime } \end{array} }\right.$$