I am writing a code to implement a function with conditions that involve partial derivatives. The out put is going to be a 3*1 matrix and will involve partial derivatives with all the three parameters. Before I could implement the actual function, I was fiddling around with a simple function as described below with no success. Could you please have a look and let me know if I have made a mistake? I think I am making a rookie mistake that would be trivial to the expert eye. Thanks a lot in advance!