題組內容
壹、簡答題:
指出下列各微分方程式的階數、次數及是否為線性:
9. $\frac{\partial^2 u}{\partial x^2}\cdot\frac{\partial^2 u}{\partial y^2}-(\frac{\partial^2 u}{\partial x\partial y})^2=0$
壹、簡答題:
指出下列各微分方程式的階數、次數及是否為線性:
9. $\frac{\partial^2 u}{\partial x^2}\cdot\frac{\partial^2 u}{\partial y^2}-(\frac{\partial^2 u}{\partial x\partial y})^2=0$