u=xsiny∂u/∂x = sinyv=lnx.cosy∂v/∂x = (1/x)cosyz=u^2.v ∂z/∂x= u^2. ∂v/∂x + 2uv. ∂u/∂x=u^2.(1/x)cosy + 2uv. siny
