Compute jacobian for function vector

Hi everyone,

I am trying to compute a jacobian for a vector function.

The vector takes a vector of two values, which are the length of a rope x(1) and the friction of the rope x(2), and returns two values, y(1) which is the turning time that I calculated through interpolation and y(2) which is the turning angle.

I have then to approximate better x(1) and x(2), but I do not know how exactly I am supposed to rewrite the function (to have two functions instead) and the corresponding jacobian matrix.

I tried the following:

Pastebin