How can we compute norm in mathematics?

Answer 1

It depends on what space your in. If its the supremum norm on a function space then just look for the max of the function. If its the euclidean norm then just takes squares, add, take the square root. Whats more interesting is that its often very hard to compute norms. For instance, even computing the norm of a 2x2 matrix is no easy problem if the matrix isn't diagonalizable. Computing the norm of a given operator on a infinite dimensional Hilbert space is very hard indeed...