I'm trying to implement the code in 9.7.2 for Quasi Newton but instead of using a single f(x) function (since there is a single element for T &func), I would like to extend it for a system of various functions e.g. f1(x)=x1-cos(x2)=0 and f2(x)=x2-3cos(x1)=0 and get the system's roots. Resulting, in multiple slope resultes as each function is different, thus I will have to manage a vector of slopes and update future linesearch points accordingly. Is this possible? Is there something that I'm missing?

Thank you

Dion