$$\text{Find}~ f_{xxyzz}~ \text{for} f(x,y,z) = z^4y^3 \ln x$$
is this right :
$$f_x = \frac{ z^4y^3 }{ x }$$
$$f_{xx} = -\frac{ z^4y^3 }{ x^2 }$$
$$f_{xxy} = -\frac{ 3z^4y^2 }{ x^2 }$$
$$f_{xxyz} = -\frac{ 12z^3y^2 }{ x^2 }$$
$$f_{xxyzz} = -\frac{ 36z^2y^2 }{ x^2 }$$

Question

$$\text{Find}~ f_{xxyzz}~ \text{for} f(x,y,z) = z^4y^3 \ln x$$
is this right :
$$f_x = \frac{ z^4y^3 }{ x }$$
$$f_{xx} = -\frac{ z^4y^3 }{ x^2 }$$
$$f_{xxy} = -\frac{ 3z^4y^2 }{ x^2 }$$
$$f_{xxyz} = -\frac{ 12z^3y^2 }{ x^2 }$$
$$f_{xxyzz} = -\frac{ 36z^2y^2 }{ x^2 }$$

hartnn · Answer

wouldn't you start by finding fz first ?

shamil98 · Answer

the problem itself is asking for
$$f_{xxyzz}$$
the first part is 
$$f_x$$

hartnn · Answer

the final answer would be same, but your method is incorrect

hartnn · Answer

no, 
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