Question

if u = log (x³+ y² +z³-3xyz)
Then show that
(d/dx +d/dy+d/dz)².u = -9/(x+y+z)²​

Answer 1

Answer:

if u = log (x³+ y² +z³-3xyz)

Then show that

(d/dx +d/dy+d/dz)².u = -9/(x+y+z)²