Drexel dragonThe Math ForumDonate to the Math Forum



Search All of the Math Forum:

Views expressed in these public forums are not endorsed by Drexel University or The Math Forum.


Math Forum » Discussions » Software » comp.soft-sys.math.mathematica

Topic: Maximize a single variable and solve for the rest
Replies: 5   Last Post: May 24, 2011 5:18 AM

Advanced Search

Back to Topic List Back to Topic List Jump to Tree View Jump to Tree View   Messages: [ Previous | Next ]
Ramiro Barrantes-Reynolds

Posts: 9
Registered: 10/14/07
Re: Maximize a single variable and solve for the rest
Posted: May 21, 2011 5:54 AM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

thank you Daniel and Bob, this solved it, please excuse my confusion.

On 5/20/11 6:49 AM, Bob Hanlon wrote:
> It makes no sense to Maximixe the LHS of an equation since it is fixed to be equal to the RHS. Presumably you are trying to maximize the variable c.
>
> r1 = 3/4;
> r2 = 1;
>
> Maximize[{c, b == c*r1, h + s + b + d == 1, d == c*r2, h == s,
> b + d<= 9/10}, {h, s, b, d, c}]
>
> {18/35, {h -> 1/20, s -> 1/20, b -> 27/70, d -> 18/35, c -> 18/35}}
>
> Solve[{b == c*r1, h + s + b + d == 1, d == c*r2, h == s, b + d<= 9/10}, {h,
> s, b, d, c}, Reals] // Quiet
>
> {{h -> ConditionalExpression[1 - (7*c)/4 + (1/2)*(-1 + (7*c)/4),
> c<= 18/35],
> s -> ConditionalExpression[(1/2)*(1 - (7*c)/4), c<= 18/35],
> b -> ConditionalExpression[(3*c)/4, c<= 18/35],
> d -> ConditionalExpression[c, c<= 18/35]}}
>
> Since you want c maximized,
>
> %[[1]] /. c -> 18/35
>
> {h -> 1/20, s -> 1/20, b -> 27/70, d -> 18/35}
>
>
> Bob Hanlon
>
> ---- Ramiro<ramiro.barrantes@gmail.com> wrote:
>
> =============
> Hello,
>
> I have a problem where I would like to solve an equation (namely (h+s+b
> +d==1) with some constraints, while maximizing for a related variable
> "c" (c<=9). Please see below, any suggestions?
>
> r1 = 3/4;
> r2 = 1;
> Block[{h, s, b, d, c},
> NMaximize[{h + s + b + d,
> b == c*r1&& h + s + b + d == 1&& d == c*r2&& h == s&&
> b + d<= 0.9}, {h, s, b, d, c}]]
>
> {1., {h -> 0.5, s -> 0.5, (3 c)/4 -> 0., c -> 0., c -> 0.}}
>
> Should I be using NSolve?
>
> Thanks in advance,
> Ramiro






Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© Drexel University 1994-2014. All Rights Reserved.
The Math Forum is a research and educational enterprise of the Drexel University School of Education.