In: Advanced Math
How would you do the work to find which PDEs below can be separated into ODEs by assuming a product of unknown functions x,y and z?
1) Uxx+Uyy+Uzz=0
2) Uxx+Uyy+Ux+Uy=0
3) Uxx+3Uxy+Uyy=0
4) Uxx+3Uxy+7Uy=0
5) x^2Uxx+yUyy=0
6) aUxy+bu=0