7(del x)/(3)=18

If u=log (x^(3) + y^(3) +z^(3) - 3xyz) , then (del u)/(del x) + (del u)/(del y) + (del u)/(del z)=

If u = log ((x ^(2) y + y ^(2) x)/(xy)) then x (del u)/( del x) + y (del u)/(del y)=

If f (x,y) is homogeneous function of degree 5 then x (del f)/(delx) +y (del f)/( del y)=

If u = sin ^(-1) ((x ^(3) + y ^3)/(x-y)) show that x (del u)/(delx) + y (del u )/(del y) = 2 tan u.

Let z(x,y) =x^(3) - 3x^(2)y^(3) , where x = se^(t), y =se^(-t), s, t in R . Find (del z)/(del s) and (del z)/(del t)

If U(x,y,z) = log(x^(3) + y^(3) +z^(3)) find (del U)/(dx) + (del U)/(dy) + (del U)/(dz)

If x = r cos theta, y = r sin theta then prove that (del (x, y)) / (del (r, theta)) xx (del (r, theta)) / (del (x, y)) = 1