((bar(v))/(u)+x)" sos "x^(del)ul(tau)^(^^)=(xp)/(hbar p)" teqp anod "x" sos "x^(del)=hbar JI*Delta9

If u=(x-y)^(4) + (y-z)^(4) + (z-x)^(4) then sum (del u)/(del x)=

If u = cos ^(-1) ((x)/(y)) prove that x (del u)/(delx) + y (del u)/(dely)=0.

If v(x,y) = log (e^(x) + e^(y)) , then (del v)/(del x) + (del v)/(del y) is equal to

If z (x + y) = x ^ (2) + y ^ (2) show that [(del z) / (del x) - (del z) / (del y)] ^ (2) = 4 [1 - (del z) / (del x) - (del z) / (del y)]

If x = r cos theta and y = r sin theta, prove that (del ^ (2) r) / (del x ^ (2)) + (del ^ (2) r) / (del y ^ (2)) = (1) / (r) [((del r) / (del x)) ^ (2) + ((del r) / (del y)) ^ (2)]

If f(x,y) =e^(xy) , then (del^(2)f)/(del x del y) is equal to

If u = x ^ (2) tan ^ (- 1) ((y) / (x)) - y ^ (2) tan ^ (- 1) ((x) / (y)), prove that (del ^ (2) u) / (del x del y) = (x ^ (2) -y ^ (2)) / (x ^ (2) + y ^ (2))

If u=(x-y)^(2) , then (del u)/(del x) + (del u)/(del y) is