This procedure computes the  (minimax) norm of a given real function f(x) on the interval [a, b]. Specifically, it computes an estimate for the value

If the second argument is a range  then the first argument is understood to be a Maple operator. If the second argument is an equation  then the first argument is understood to be an expression in the variable x.

If the third argument 'xmax' is present then it must be a name. Upon return, its value will be an estimate for the value of x where the maximum of  is attained.

Various levels of user information will be displayed during the computation if infolevel[infnorm] is assigned values between 1 and 4.

The command with(numapprox,infnorm) allows the use of the abbreviated form of this command.