My result doesn't agree with results from online calculators
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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
asked Dec 31 '18 at 1:14
DDMCDDMC
13016
$endgroup$
add a comment |
$begingroup$
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
asked Dec 31 '18 at 1:14
DDMCDDMC
13016
$endgroup$
1
$begingroup$
Your solution looks fine to me. BTW: you can useleqto get $leq$ andgeqto 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
add a comment |
$begingroup$
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
asked Dec 31 '18 at 1:14
DDMCDDMC
13016
$endgroup$
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
asked Dec 31 '18 at 1:14
DDMCDDMC
13016
asked Dec 31 '18 at 1:14
DDMCDDMC
13016
edited Dec 31 '18 at 1:29
DDMC
asked Dec 31 '18 at 1:14
DDMCDDMC
13016
asked Dec 31 '18 at 1:14
DDMCDDMC
13016
asked Dec 31 '18 at 1:14
DDMCDDMC
13016
13016
1
$begingroup$
Your solution looks fine to me. BTW: you can useleqto get $leq$ andgeqto 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
add a comment |
1
$begingroup$
Your solution looks fine to me. BTW: you can useleqto get $leq$ andgeqto 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
add a comment |
1 Answer
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$begingroup$
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
answered Dec 31 '18 at 1:26
LinAlgLinAlg
10.1k1521
$endgroup$
add a comment |
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$begingroup$
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
answered Dec 31 '18 at 1:26
LinAlgLinAlg
10.1k1521
$endgroup$
add a comment |
$begingroup$
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
answered Dec 31 '18 at 1:26
LinAlgLinAlg
10.1k1521
$endgroup$
add a comment |
$begingroup$
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
answered Dec 31 '18 at 1:26
LinAlgLinAlg
10.1k1521
$endgroup$
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
answered Dec 31 '18 at 1:26
LinAlgLinAlg
10.1k1521
answered Dec 31 '18 at 1:26
LinAlgLinAlg
10.1k1521
answered Dec 31 '18 at 1:26
LinAlgLinAlg
10.1k1521
answered Dec 31 '18 at 1:26
LinAlgLinAlg
10.1k1521
10.1k1521
add a comment |
add a comment |
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1
$begingroup$
Your solution looks fine to me. BTW: you can use
leqto get $leq$ andgeqto 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