(a) Let F1 = x^2 z^ and F2 = x x^ + y y^ + z z^. Calculate the divergence and curl of F1 and F2. Which one can be written as the gradient of a scalar? Find a scalar potential that does the job. Which one can be written as the curl of a vector? Find a suitable vector potential.
(b) Show that F3 = yz x^ + zx y^ + xy z^ can be written both as the gradient of a scalar and as the curl of a vector. Find scalar and vector potentials for this function.