زولديك
21-09-2010, 20:32
بسم الله الرحمن الرحيم
إدا كانت http://latex.codecogs.com/gif.latex?f(r,\theta )=r^n.sin(n\theta ) فبرهن أن
http://latex.codecogs.com/gif.latex?\frac{\partial^2 f}{\partial r^2}+(1/r)\frac{\partial }{\partial r}+(1/r^2)\frac{\partial^2 }{\partial \theta ^2}=0
إدا كانت http://latex.codecogs.com/gif.latex?f(r,\theta )=r^n.sin(n\theta ) فبرهن أن
http://latex.codecogs.com/gif.latex?\frac{\partial^2 f}{\partial r^2}+(1/r)\frac{\partial }{\partial r}+(1/r^2)\frac{\partial^2 }{\partial \theta ^2}=0