When is statment true?
\(\displaystyle \L
\frac{{\partial ^3 f}}{{\partial ^2 y\partial x}} =
\frac{{\partial ^3 f}}{{\partial ^2 x\partial y}}\)
All I know is that if the funtion is continous.. so are the partial derviative...
Would i prove the orginial function:
\(\displaystyle \L f( x , y ).... defined ....at ....... x(0) y(0)\)
\(\displaystyle \L\\\lim_{(x,y)\to\ x(0),y(0)} f( x , y ) ....... Exists\)
\(\displaystyle \L\\\lim_{(x,y)\to\ x(0),y(0)} f( x , y ) = f( x(0) , y(0) )\)
is it suffice to say that on an exam?