here we did not need to enter the jacobian manually, SymPy did that for us.
For expressions containing transcendental functions we need to provide a
“backend” keyword arguemnt to enable symbolic derivation of the jacobian:

License

The source code is Open Source and is released under the simplified 2-clause BSD license. See LICENSE for further details.
Contributors are welcome to suggest improvements at https://github.com/bjodah/pyneqsys