Re: Maximisation question

*To*: mathgroup at smc.vnet.net*Subject*: [mg126562] Re: Maximisation question*From*: Bill Rowe <readnews at sbcglobal.net>*Date*: Sat, 19 May 2012 05:45:13 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com

On 5/18/12 at 5:23 AM, jack.j.jepper at googlemail.com (J.Jack.J.) wrote: >For any integer j, suppose we have a function f(j). Then how would I >find the highest f(i) such that 100 <= f(i) <0 ? With thanks in >advance. Use NMaximize. For example: In[14]:= NMaximize[{4 x - .57 x^2, x \[Element] Integers}, {x}] Out[14]= {6.88,{x->4}} and by doing In[15]:= Solve[D[4 x - .57 x^2, x] == 0, x] Out[15]= {{x->3.50877}} you can see the true maximum is not an integer