Let be a regular surface and let . then (U,F,V) is a local parametrisation of S at p. Let

Define , with . Then is a basis of the tangent plane

Here , i.e the jacobian then applied to

I am having a lot of trouble trying to show that

where .

I was wondering if anyone could give me some advice on how to think about this, I am very weak in this type of calculus. Thanks very much