@Scot Gould 

I already know these instructions and couldn't do much with them. My goal is to transform tasks that were previously solved with the help of pen and paper and other programs into the much more powerful Maple. I'm currently trying to do this as a practice exercise with an old exam question that was set for the Abitur in a distant country ;-). Since I don't know a structural overview of Maple, I find it difficult to understand why "packages" are often required before entering a command.

I'm currently trying to check the positive definiteness of the matrix generated using "Hessian". The "IsDefinite" command produces an incomprehensible error message. I'm asking for advice.