My result doesn't agree with results from online calculators












0












$begingroup$


I'm doing an exercise about linear programming, but my answer doesn't agree with the answer from online calculators like this and this. Below is the problem statement:
$$Minimize: u = 4x - 3y, s.t.$$
$$y le -x + 1$$
$$y le x + 1$$
$$y ge 0$$



I found 3 corner: (-1,0), (0,1), (1,0) and min = -4 at (-1,0), but these calculators gives me the answer -3 at (0,1). Did I miss anything when solving this problem?






linear-programming







share|cite|improve this question











$endgroup$








  • 1




    $begingroup$
    Your solution looks fine to me. BTW: you can use leq to get $leq$ and geq to get $geq$.
    $endgroup$
    – Dave
    Dec 31 '18 at 1:22










  • $begingroup$
    Were you perhaps entering $xgeq 0$ as a constraint as well?
    $endgroup$
    – Dave
    Dec 31 '18 at 1:24
















0












$begingroup$


I'm doing an exercise about linear programming, but my answer doesn't agree with the answer from online calculators like this and this. Below is the problem statement:
$$Minimize: u = 4x - 3y, s.t.$$
$$y le -x + 1$$
$$y le x + 1$$
$$y ge 0$$



I found 3 corner: (-1,0), (0,1), (1,0) and min = -4 at (-1,0), but these calculators gives me the answer -3 at (0,1). Did I miss anything when solving this problem?






linear-programming







share|cite|improve this question











$endgroup$








  • 1




    $begingroup$
    Your solution looks fine to me. BTW: you can use leq to get $leq$ and geq to get $geq$.
    $endgroup$
    – Dave
    Dec 31 '18 at 1:22










  • $begingroup$
    Were you perhaps entering $xgeq 0$ as a constraint as well?
    $endgroup$
    – Dave
    Dec 31 '18 at 1:24














0












0








0





$begingroup$


I'm doing an exercise about linear programming, but my answer doesn't agree with the answer from online calculators like this and this. Below is the problem statement:
$$Minimize: u = 4x - 3y, s.t.$$
$$y le -x + 1$$
$$y le x + 1$$
$$y ge 0$$



I found 3 corner: (-1,0), (0,1), (1,0) and min = -4 at (-1,0), but these calculators gives me the answer -3 at (0,1). Did I miss anything when solving this problem?






linear-programming







share|cite|improve this question











$endgroup$




I'm doing an exercise about linear programming, but my answer doesn't agree with the answer from online calculators like this and this. Below is the problem statement:
$$Minimize: u = 4x - 3y, s.t.$$
$$y le -x + 1$$
$$y le x + 1$$
$$y ge 0$$



I found 3 corner: (-1,0), (0,1), (1,0) and min = -4 at (-1,0), but these calculators gives me the answer -3 at (0,1). Did I miss anything when solving this problem?






linear-programming




linear-programming






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Dec 31 '18 at 1:29







DDMC

















asked Dec 31 '18 at 1:14









DDMCDDMC

13016




13016








  • 1




    $begingroup$
    Your solution looks fine to me. BTW: you can use leq to get $leq$ and geq to get $geq$.
    $endgroup$
    – Dave
    Dec 31 '18 at 1:22










  • $begingroup$
    Were you perhaps entering $xgeq 0$ as a constraint as well?
    $endgroup$
    – Dave
    Dec 31 '18 at 1:24














  • 1




    $begingroup$
    Your solution looks fine to me. BTW: you can use leq to get $leq$ and geq to get $geq$.
    $endgroup$
    – Dave
    Dec 31 '18 at 1:22










  • $begingroup$
    Were you perhaps entering $xgeq 0$ as a constraint as well?
    $endgroup$
    – Dave
    Dec 31 '18 at 1:24








1




1




$begingroup$
Your solution looks fine to me. BTW: you can use leq to get $leq$ and geq to get $geq$.
$endgroup$
– Dave
Dec 31 '18 at 1:22




$begingroup$
Your solution looks fine to me. BTW: you can use leq to get $leq$ and geq to get $geq$.
$endgroup$
– Dave
Dec 31 '18 at 1:22












$begingroup$
Were you perhaps entering $xgeq 0$ as a constraint as well?
$endgroup$
– Dave
Dec 31 '18 at 1:24




$begingroup$
Were you perhaps entering $xgeq 0$ as a constraint as well?
$endgroup$
– Dave
Dec 31 '18 at 1:24










1 Answer
1






active

oldest

votes


















2












$begingroup$

The online calculators assume nonnegativity. If you write $x$ as the difference of two nonnegative numbers, your first calculator gives the right answer



Minimize p = 4x1-4x2-3y subject to

x1-x2+y <= 1

-x1+x2+y <= 1





share|cite|improve this answer









$endgroup$













    Your Answer





    StackExchange.ifUsing("editor", function () {
    return StackExchange.using("mathjaxEditing", function () {
    StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
    StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
    });
    });
    }, "mathjax-editing");

    StackExchange.ready(function() {
    var channelOptions = {
    tags: "".split(" "),
    id: "69"
    };
    initTagRenderer("".split(" "), "".split(" "), channelOptions);

    StackExchange.using("externalEditor", function() {
    // Have to fire editor after snippets, if snippets enabled
    if (StackExchange.settings.snippets.snippetsEnabled) {
    StackExchange.using("snippets", function() {
    createEditor();
    });
    }
    else {
    createEditor();
    }
    });

    function createEditor() {
    StackExchange.prepareEditor({
    heartbeatType: 'answer',
    autoActivateHeartbeat: false,
    convertImagesToLinks: true,
    noModals: true,
    showLowRepImageUploadWarning: true,
    reputationToPostImages: 10,
    bindNavPrevention: true,
    postfix: "",
    imageUploader: {
    brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
    contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
    allowUrls: true
    },
    noCode: true, onDemand: true,
    discardSelector: ".discard-answer"
    ,immediatelyShowMarkdownHelp:true
    });


    }
    });














    draft saved

    draft discarded


















    StackExchange.ready(
    function () {
    StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3057350%2fmy-result-doesnt-agree-with-results-from-online-calculators%23new-answer', 'question_page');
    }
    );

    Post as a guest















    Required, but never shown

























    1 Answer
    1






    active

    oldest

    votes








    1 Answer
    1






    active

    oldest

    votes









    active

    oldest

    votes






    active

    oldest

    votes









    2












    $begingroup$

    The online calculators assume nonnegativity. If you write $x$ as the difference of two nonnegative numbers, your first calculator gives the right answer



    Minimize p = 4x1-4x2-3y subject to
    
x1-x2+y <= 1
    
-x1+x2+y <= 1





    share|cite|improve this answer









    $endgroup$


















      2












      $begingroup$

      The online calculators assume nonnegativity. If you write $x$ as the difference of two nonnegative numbers, your first calculator gives the right answer



      Minimize p = 4x1-4x2-3y subject to
      
x1-x2+y <= 1
      
-x1+x2+y <= 1





      share|cite|improve this answer









      $endgroup$
















        2












        2








        2





        $begingroup$

        The online calculators assume nonnegativity. If you write $x$ as the difference of two nonnegative numbers, your first calculator gives the right answer



        Minimize p = 4x1-4x2-3y subject to
        
x1-x2+y <= 1
        
-x1+x2+y <= 1





        share|cite|improve this answer









        $endgroup$



        The online calculators assume nonnegativity. If you write $x$ as the difference of two nonnegative numbers, your first calculator gives the right answer



        Minimize p = 4x1-4x2-3y subject to
        
x1-x2+y <= 1
        
-x1+x2+y <= 1






        share|cite|improve this answer












        share|cite|improve this answer



        share|cite|improve this answer










        answered Dec 31 '18 at 1:26









        LinAlgLinAlg

        10.1k1521




        10.1k1521






























            draft saved

            draft discarded




















































            Thanks for contributing an answer to Mathematics Stack Exchange!


            • Please be sure to answer the question. Provide details and share your research!

            But avoid …



            • Asking for help, clarification, or responding to other answers.

            • Making statements based on opinion; back them up with references or personal experience.


            Use MathJax to format equations. MathJax reference.


            To learn more, see our tips on writing great answers.




            draft saved


            draft discarded














            StackExchange.ready(
            function () {
            StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3057350%2fmy-result-doesnt-agree-with-results-from-online-calculators%23new-answer', 'question_page');
            }
            );

            Post as a guest















            Required, but never shown





















































            Required, but never shown














            Required, but never shown












            Required, but never shown







            Required, but never shown

































            Required, but never shown














            Required, but never shown












            Required, but never shown







            Required, but never shown







            -

            Popular posts from this blog

            Probability when a professor distributes a quiz and homework assignment to a class of n students.

            Image
            0 0 $begingroup$ Need help with this problem. Suppose our lazy professor collects a quiz and a homework assignment from a class of n students one day, then distributes both the quizzes and the homework assignments back to the class in a random fashion for grading. Each student receives one quiz and one homework assignment to grade. (a) What is the probability that every student receives someone else's quiz to grade, and someone else's homework to grade? (b) What is the probability that no student receives both their own quiz and their own homework assignment to grade? In this case, some students may receive their own quiz, and others may receive their own homework assignment. (c) Compute the limiting probability as n approaches infinity in each case. ...
            Read more

            Aardman Animations

            Image
            Aardman Animations, Ltd. Aardman Animations Tipo privada Atividade Animação em stop-motion , Animação em CGI Fundação 1972 Fundador(es) Peter Lord David Sproxton Sede Bristol, Inglaterra  Reino Unido Proprietário(s) Dreamworks Pessoas-chave Peter Lord David Sproxton Nick Park Divisões Aardman Features Aardman Digital Aardman Commercials Aardman Broadcast Aardman International Aardman Rights Aardman Effects Aardman 3-D Systems Aardman Nathan Love AardBoiled Website oficial aardman.com ...
            Read more

            Are they similar matrix

            Image
            0 $begingroup$ Do $begin{bmatrix} 0&i&0\0&0&1\0&0&0 end{bmatrix} $ and $begin{bmatrix} 0&0&0\-i&0&0\0&1&0 end{bmatrix} $ are similar.Is this True/false Clearly both are nilpotent and one is conjucate transpose of other but how to know if they are similar.i'm stuck. Please help me linear-algebra vector-spaces eigenvalues-eigenvectors generalizedeigenvector share | cite | improve this question edited Dec 10 '18 at 6:38 Vasanth Kris asked Dec 10 '18 at 6:19 ...
            Read more