Crap, I'm really sorry, I completely messed up part ii.
ii was supposed to say g(x1, x2) = (cos x2, x1x2^3) It's hard to see, but what the right side says is cosine of xsubscript2, xsubscript1xsubscript 2, to the exponent 3.
Thanks for your example! Based on that, I'm guessing that I can do...