Assume that all the given functions have continuous second-order partial derivatives.
If z=f(x,y), where x=r^(2)+s^(2) and y=5rs, find del^(2)(z)/(delrdels). (Compare with this example.)
(del^(2)z)/(delrdels)=β»(del^(2)z)/(delx^(2))+β»(del^(2)z)/(dely^(2))+β»(del^(2)z)/(delxdely)+β»(delz)/(dely)
aras Ox2 + az Assume that all the given functions have continuous second-order partial derivatives. dy2 + axay az