ISI 2006 ME-1

[RichaS]

The answer is 0, How to go about this?

[Abhitesh]

Let a=x-y ; b=y-z ; c=z-x
du/dx = du/da*da/dx + du/db*db/dx + du/dc*dc/dx = du/da - du/dc
du/dy = -du/da + du/db
du/dz = -du/db +du/dc

[RichaS]

Thanks so much!