Matrix inverses are often used in describing matrix algorithms. However, in practice, it is almost never necessary to calculate the inverse of a matrix explicitly. In almost every case, the problem can be solved much more efficiently by using a factorization. Nevertheless, for those rare occasions when you actually need the explicit inverse, a function is provided for its calculation. For example, to find the inverse of a double precision symmetric matrix whose factorization is the variable fact of type RWSymFact<double>, you use: