Had had closed the session in the meanwhile? That would explain why rootsFinal is not recognized any more.
rootsFinal
I need to compute f on a "grid" with many values of $a,b,c,d$. Thanks for the advice
That was it, feeling dumb now. Is this the correct way to make a function out of an expression dependent on parameters or is there a better way? I will have to compute it on a grid of values
