1(a) For the vector function q(x,y,z)=(xy-z2)i +(yz+x2)j +(xz-y2)k calculate (i)∇ . q (ii) ∇ . q (iii) ∇ x (∇ x q) verify that the identity ∇ x (∇ x q) = ∇(∇ . q - ∇2q i have answers of y+z+x,(-3y,-3z,1x) and (3,-1,3) respectivly for the first part but cant fathom the second part, mainly because subbing back in (which i presume is how this is shown) the part where i sub in y+z+x for (∇ . q) what do i now do with ∇ . (y+z+x). the fact that i end up with this leads me to beleive that subbing in is wrong but if it is i really dont know where to go, help please!