Questions tagged [findinstance]
The findinstance tag has no usage guidance.
68
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How to return only the negative complex solutions of DSolve or using FindInstance?
I am using DSolve to find the solutions to two differential equations. The problem is from the first solution, I only want the solution that includes a negative ...
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54
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Problem in solving the non-linear equation
Is there any other way to solve an equation rather than solve command also without findroot command in Mathematica? Because the Solve command is not returning any ...
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50
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How to solve inequality equations of kappa modifiers using FindInstance command?
Here, ub are signal strength values while ube is error value. similarly, other values. THbb and other are higgs decay width values. these values are required values for making inequalities mentioned ...
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4
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How can I formulate this simple mathematical riddle into a computable Wolfram Language query?
I'm trying to formulate the below question into a computable wolfram language solution, but can't seem to get it right.
Question:
Place three piles of matches on a table, one with 11 matches, the ...
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How can I reduce the time to compile this solve?
I want to find five integer numbers $a, b, c, d, e$ so that $a+ b+ c + d + e = 9 k$ and none of two number in which are equal. I tried.
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How can we find the appropriate values of unknowns such that the following expression must be a real number? `FindInstance`
Question: I have some mathematical functions including various parameters. I want to find instances for the parameters such that the function must be in a real domain after substituting the values of ...
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Finding only non-negative roots with FindRoot
Given an arbitrary function F, how do I force FindRoot to look only for non-negative roots, returning nothing otherwise?
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Finding the similarity transformation between two symbol matrices
I have two symbol matrices mA and mB, which are similar matrices.
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Can I use FindInstance to prove an algebraic identity?
This question arose from a [now removed] MathOverflow discussion, where a Null result from a FindInstance query was used to prove that $f(x_1,x_2,\ldots x_n)\neq 0$ has no solution in $\mathbb{R}$. My ...
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Calculating eigenvalues and solving inequalities with parameters
I would like to calculate b in terms of c and a, in order to satisfy the following conditions:
...
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50
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An error occurred while using FindInstance to find a matrix that meets the constraint conditions
I want to use MMA to prove an exercise in textbook: mA is a n-level square matrix.
Proof: mA.mA==mA is true if and only if ...
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112
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Mathematica generating 'incorrect' Cuboids
Mathematica 13.1 for some reason gives an error for the following code:
...
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Finding a (sufficient) condition for an inequality - Solve takes too long
I have the following inequality
$ 2 \sqrt{2} n^2 \sqrt{\frac{r}{r-1}} \exp \left(2^{-\frac{\sqrt[3]{\log (n)}}{10 \sqrt[3]{\log (r)}}} \left(\frac{1}{r+1}\right)^{-\frac{\sqrt[3]{\log
(n)}}{10 \...
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Solving a Simple 'Sum and Product' Problem
I am trying to solve a simple 'sum and product' problem. Basically, the sum of four prices and the product of those four prices are numerically equal (you must, of course, disregard the units). The ...
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135
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FunctionDomain and FindInstance problem
I have some functions including many real parameters as follows:
For example,
...
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How to find rational roots of a polynomial in 5 variables in a cube
I am trying to find rational numbers $m,k,l,o,z,R$ such that
R^12 - (k l^2 m - l m^2 o - k^2 l z + l o z) R^6 + o^3*z^3 == 0
in the following cube:
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How can I solve this system of 6 simple quadratic diophantine equations in four variables?
I generated this text file containing tuples $(\sqrt{s}, \sqrt{t}, \sqrt{u}, s,t,u,t+u,t+u-s,t-s)$ where the six variables $s,t,u,t+u,t+u-s,t-s$ are all squares. An excerpt of the data set is:
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Challenges and Opportunities of `FindInstance` Command
I'm testing the FindInstance capabilities and ran into one problem that behaves similarly with different types of inequalities. I calculate two points satisfying ...
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FindInstance specifying reals increases the time significantly and gives errors
I was wondering if there is any way to put time constraint on FindInstance.
My problem is as follows: I want to find two, $2 \times 2$ matricies $A,B$ given $Tr(A)$, $Tr(B)$, $TR(AB)$, $Det(A)$ and $...
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Tips to help FindInstance with a lot of complicated inequalities
I'm trying to find a numerical instance (I don't need arbitrarily high precision) of solution to 7 relatively complicated inequalities (plus the region specification) involving 8 variables.
The ...
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Defining new Domain for variables
I am trying to define a new Domain for variables to use with functions like FindInstance or Solve. For example, If I wanted to solve x+y+z=1 over the Reals, I'd get a large solution space. But If I ...
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How to calculate multiple solutions from big to small with FindInstance funtion
I want to find the nearest 50(or 80, even 100)solutions under 1.4628 from big to small, I tried FindInstance function in MMA, but still cannot get the desired results I need.Here is my code:
...
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Finding all solutions to coupled algebraic equations without exhaustive enumeration
A Cambridge University mathematics interview question states:
Find all $a,b,c,d,e,f \in \mathbb{N}$ such that
$$a + b + c = d \cdot e \cdot f$$
and
$$d + e + f = a \cdot b \cdot c$$
(There are a ...
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Elementary number theory problem and FindInstance
Find $\{ m,n \} \in \mathbb{Z}$ such that $m \neq n$ and $m^n = n^m$.
This has (unordered) solutions $\{ 2, 4 \}$ and $\{ -2, -4 \}$, as can be easily checked.
I'm of course hoping for an analytic ...
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Solve equation with summation and factorial over Integers
Find all $\{ m, n \} \in \mathbb{Z}^+$ such that
$$\sum\limits_{k=1}^m k! = n^2 .$$
The two solutions are $\{ m,n \} = \{ 1,1 \}$ and $\{ 3,3 \}$, as can be confirmed. Here is how to solve this ...
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Find smallest instance satisfying certain inequalities
I need a "clean" way to find the smallest solution to some (in)equalities given by Reduce and containing only one variable ...
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99
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Control evaluation for functional constraints
I'm trying to understand how to use Mathematica to find a solution subject to constraints, where one of the constraints is specified as a predicate function. But I don't know how to control evaluation ...
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61
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Restrict FindInstance to exact value
I would like to restrict the FindInstance function to exact values (ex. 2Pi/3)
The following doesn't work
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Why does `FindInstance` refuse to find a second instance, in a number theory problem?
Hi I am looking for reversible Markov generating matrices of order three, whose upper (2,2) block has integer eigenvalues. There are 5 free parameters; I specified 2
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Does FindInstance traverse the entire domain?
If the result of FindInstance[expr<=0,vars,dom] is empty set, can it mean that expr is always greater than ...
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How to show all global minimizers?
This is a follow-up to this question and I'm aware of this question for the local minimizers case.
Consider, for $0\leq \epsilon\leq 1$ and $0<q,p<1$, the function
$$
\begin{align}
f(\...
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Finding multiple minimizers
Is it possible to find all (or as many as possible) minimizers of a given function? For example, minimizing the function $\cos(\pi(p-q))+\cos(\pi(q+p))$ for $-3\leq p,q\leq 3 $ can be done using ...
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FindInstance won't compute this simple expression
I want to find instances where this standard 3x3 symmetric matrix has only positive eigenvalues.
So I run ...
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Find a non-convex instance for a non-convex set function with FindInstance
Let $f$ be a non-convex set function defined on a set $L$.
Hence there are subsets $A,B\subseteq L$ such that
$$f(A)+f(B)>f(A\cup B)+f(A\cap B).$$
I tried to use FindInstance function to find a non-...
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Obtain fairly sampled data set subject to a condition?
I need to obtain a random distribution of some parameters {t1,t2,t3} subject to a set of conditions. For example,
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FindInstance taking too long
I just started to use Wolfram Alpha Notebook Edition. I am using FindInstance command to evaluate the sign of an expression with $8$ variables, under simple constraints, but it takes too much time. Do ...
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My Program using NSolve and FindInstance has been running for days without a solution
I have a system of 5 non-linear equations and 5 unknowns (p1,p2,p3,p4,p5 bellow), and a few inequalities. I am trying to understand whether the solution is unique.
For this purpose, I tried to run ...
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System of 15 equations in 23 variables
$$
1-k_0^2=0, \frac{1}{2} \left(-7 \alpha ^2+38 \alpha +2 c_3 (\alpha +\beta-3)+2 c_6-2 k_1^2-2 k_5^2-48\right)=0, c_5-k_2^2-k_{10}^2=0, c_8(\alpha +\beta -5)+5 c_{10}-k_3^2-k_6^2-k_8^2-k_{11}^2-2 k_2 ...
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Solve inequalities
I use FindInstance to find a set of real parameters to satisfy the following inequality
$-3 c_{11}-k_4^2-k_7^2-k_9^2>0$,
$$
-4 \alpha^6+84 \alpha^5-721 \alpha^4+3228 \alpha^3-7924 \alpha^2+10080 \...
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How can I find some values for which an expression is real?
I've a complicated expression which depends on several variables. I want to find some values for those variables such that the complicated expression is real. How can I do that?
The obvious command ...
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Turning FindInstance into True or False
I have a function where I input a certain vector of parameters and it gives me the output of 16 FindInstances. So, a typical output will look something like this
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Finding a solution to a modular problem efficiently
I want to find a naïve hash function of the form Mod[a x + b, 2^p] which would produce a value less or equal to v for all ...
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Why does FindInstance take so long: It is faster with more restrictions than with less?
A support case with the identification [CASE:4347836] was created.
I just noted this little puzzle on twitter by Brillant.org:
\begin{align} A B C\\+ BCA\\ = CDE \end{align}
Given that $A$ is even ...
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FindInstance confused by CoprimeQ
For some reason when I type
FindInstance[a + b == c && CoprimeQ[a, b, c] == True, {a, b, c}, Integers]
Mathematica just immediately returns my input as ...
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147
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FindInstance Returns "Aborted" [closed]
Edit: Apologies, the question needs to be reworked, because I cannot reproduce the original problem using this code.
I don't delete the question, in case someone is preparing an answer at the moment.
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