Chapter 9 - Multiveriable Calculus - 9.2 Partial Derivatives - 9.2 Exercises - Page 478: 38

$f_{x}(x,y,z)=18x^{2}-2xy^{2}$ $f_{y}(x,y,z)=-2x^{2}y+5y^{4}$ $f_{z}(x,y,z)=0$ $f_{yz}(x,y,z)=0$

$f_{x}(x,y,z)=18x^{2}-2xy^{2}$ $f_{y}(x,y,z)=-2x^{2}y+5y^{4}$ $f_{z}(x,y,z)=0$ Differentiate $f_{y}(x,y,z)$ with respect to z to get $f_{yz}(x,y,z)$ $f_{yz}(x,y,z)=0$