Questions tagged [findinstance]
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83 questions
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FindInstance returns no solution when solving for odd integers
In a question on Mathematics SE, a comment observes that Mathematica 14.3 reports non-solvability of (a relaxation of) the given problem
Is there an odd $a \neq 1$ s.t. $2^k + 1 | a^k - 1$ for all $k ...
- 3,172
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For this 2x2 matrix, how to find real parameters such that its determinant and trace vanish simultaneously?
I have a matrix
M = {{-num11/(2*den), num12/den}, {num12/den, num22/(2*den)}};
with
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- 698
5
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Finding real solutions for a complex rational expression with constraints in Mathematica
I have a rather large rational expression exp involving real variables $x_1, x_2, \dots, x_{10}$. The expression is of the following form
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FindInstance with Exists and ForAll
I am doing a research into magic and quasimagic squares and I want to get instances with the function FindInstance. This is a template of the command used for the 4x4 square:
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FindInstance has difficulty computing more than one solution to a certain type of trigonometric inequality
FindInstance has difficulty computing more than one solution to this type of trigonometric inequality:
$$\arccos(\cos(\theta_1 - \theta_2)) + \arccos(\cos(\theta_2 -...
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FindInstance and Integers option
I am looking for integer solutions of
$$a^3 + b + 1 = (b^2 - c^2)^2$$
Some solutions are
$$(a, b, c) = (6,8,7); (46,7,19);(665, 8575, 8584)$$
I tried this with the FindInstance command as
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- 3,638
0
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1
answer
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FindInstance Not Stopping
I am trying to use FindInstance to find a solution to a system of equations. It does not return the empty set, but instead continues to run. Does this mean that there is no solution? Or perhaps I am ...
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FindInstance is not able to find a solution that can be found easily by random substitution
Why is FindInstance not able to find any instance when random substitution finds them very quickly.
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Improve FindInstance, or better yet just Solve!
This one is seemingly not that complex, yet I am not getting Mathematica to return a solution in a timely manner: (I have 2 variables, t - an angle and k a length)
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- 1,747
8
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How to improve code finding x+y+z+w=40 to generate numbers 1 through 40?
Edit: Appended work to find generators for any number as per azerbajdzan and ubpdqn. See below
Ran into this problem and was wondering if there is a more elegant and concise way of coding this if ...
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Why doesn't `FindInstance` work in finding Heronian triangle?
I was trying to find a triangle whose side lengths are all positive integers and area is rational number (similar to Heronian triangle) with FindInstance, but it ...
- 2,384
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FindInstance for Reals
I am trying to find the total number of solutions to: Floor[x]*Ceiling[x]=x^2 between 0 and 100
Now when we do this for Integers, it's just fine with a 100 result:
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- 1,747
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2
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350
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1
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1
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Why FindInstance does not find this solution?
Do you think FindInstance should have found this solution?
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- 157k
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Checking Positivity
This is my matrix:
H = {{2*a1*p4, -p5*a2, p3*a1, 0},{-p5*a2, 2*a2*w1, -p2, -p1},{p3*a1, -p2, 2*a3*w2, 0},{0, -p1*a4, 0, 2*a4*w3}}
Where a1,a2,a3,a4 are non-...
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