How do I do this? ------ Find the four second partial derivatives. Observe that the second mixed partials are equal. z = 4 ln(x − y)

Question

 Find the four second partial derivatives. Observe that the second mixed partials are equal. z = 4 ln(x − y)

Answer 1

z = 4 ln(x − y)

dz/dx=4/(x-y)

d²z/dx²=-4/(x-y)²

 

dz/dy=-4/(x-y)

d²z/dy²=-4/(x-y)²=d²z/dx²