u=f ( xy,xe^y ) 求 Ә2u / ӘxӘy

u=f ( xy,xe^y ) 求 Ә2u / ӘxӘy
u=f ( xy,xe^y ) 求 Ә2u / ӘxӘy

u=f ( xy,xe^y ) 求 Ә2u / ӘxӘy
设xy为w,设xe^y为m Әu/Әy=F'(w)(xy,xe^y)x+F'(m)(xy,xe^y)xe^y
Ә2u/ӘxӘy=F''(w)(w)(xy,xe^y)xy+F''(w)(m)(xy,xe^y)xe^y+F'(w)(xy,xe^y)+
F''(m)(w)(xy,xe^y)xye^y+F''(m)(m)(xy,xe^y)xe^2y+F'(xy,xe^y)e^y