Questions tagged [findinstance]

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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 ...
RudyJD's user avatar
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0 answers
54 views

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 ...
supragyan priyadarshinee's user avatar
1 vote
1 answer
50 views

Randomized values for FindInstance

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mdansfo's user avatar
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0 answers
27 views

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 ...
Mihir's user avatar
  • 1
4 votes
4 answers
202 views

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 ...
Jason Roell's user avatar
3 votes
2 answers
248 views

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. ...
John Paul Peter's user avatar
4 votes
1 answer
83 views

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 ...
RF_1's user avatar
  • 672
0 votes
1 answer
76 views

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?
sam wolfe's user avatar
  • 4,147
1 vote
0 answers
69 views

Finding the similarity transformation between two symbol matrices

I have two symbol matrices mA and mB, which are similar matrices. ...
lotus2019's user avatar
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3 votes
0 answers
70 views

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 ...
Carlo Beenakker's user avatar
1 vote
0 answers
51 views

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: ...
Wiki's user avatar
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0 votes
0 answers
50 views

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 ...
lotus2019's user avatar
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2 votes
1 answer
112 views

Mathematica generating 'incorrect' Cuboids

Mathematica 13.1 for some reason gives an error for the following code: ...
Liam Baker's user avatar
1 vote
1 answer
93 views

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 \...
black's user avatar
  • 251
9 votes
5 answers
844 views

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 ...
JoeMarino's user avatar
  • 151
1 vote
2 answers
135 views

How to find a set of solution of the inequality?

There exists a,b,c,d,e such that ...
lapcal's user avatar
  • 531
2 votes
1 answer
134 views

Strange error in FindInstance result

I was running the following code ...
user58955's user avatar
  • 617
3 votes
1 answer
129 views

FunctionDomain and FindInstance problem

I have some functions including many real parameters as follows: For example, ...
Eric_Jansen's user avatar
2 votes
0 answers
96 views

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: ...
2132123's user avatar
  • 647
3 votes
1 answer
143 views

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: ...
Eldar Sultanow's user avatar
4 votes
3 answers
179 views

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 ...
dtn's user avatar
  • 2,364
0 votes
0 answers
69 views

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 $...
2132123's user avatar
  • 647
0 votes
0 answers
47 views

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 ...
GaloisFan's user avatar
  • 395
2 votes
0 answers
95 views

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 ...
Matthew Crawford's user avatar
0 votes
1 answer
73 views

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: ...
Levin Koo's user avatar
0 votes
2 answers
186 views

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 ...
David G. Stork's user avatar
2 votes
4 answers
151 views

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 ...
David G. Stork's user avatar
8 votes
2 answers
182 views

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 ...
David G. Stork's user avatar
3 votes
1 answer
133 views

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 ...
Oliver Miller's user avatar
1 vote
1 answer
99 views

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 ...
algal's user avatar
  • 113
0 votes
2 answers
61 views

Restrict FindInstance to exact value

I would like to restrict the FindInstance function to exact values (ex. 2Pi/3) The following doesn't work ...
user3558075's user avatar
1 vote
0 answers
61 views

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 ...
florin's user avatar
  • 1,592
2 votes
1 answer
107 views

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 ...
user73722's user avatar
1 vote
1 answer
88 views

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(\...
sam wolfe's user avatar
  • 4,147
3 votes
0 answers
124 views

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 ...
sam wolfe's user avatar
  • 4,147
6 votes
4 answers
295 views

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 ...
Jesper Johansson's user avatar
1 vote
1 answer
42 views

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-...
hxiao's user avatar
  • 867
1 vote
1 answer
63 views

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, ...
naomig's user avatar
  • 343
2 votes
0 answers
150 views

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 ...
Penelope Benenati's user avatar
1 vote
2 answers
209 views

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 ...
Gabi Gayer's user avatar
0 votes
0 answers
131 views

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 ...
LCH's user avatar
  • 189
1 vote
1 answer
109 views

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 \...
LCH's user avatar
  • 189
1 vote
1 answer
185 views

FindInstance runtime is too long

...
mtheorylord's user avatar
0 votes
2 answers
139 views

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 ...
Allure's user avatar
  • 625
0 votes
0 answers
67 views

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 ...
Amanda's user avatar
  • 199
0 votes
0 answers
67 views

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 ...
kirma's user avatar
  • 18.7k
3 votes
1 answer
222 views

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 ...
gwr's user avatar
  • 13k
2 votes
1 answer
54 views

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 ...
volcanrb's user avatar
  • 373
0 votes
1 answer
147 views

How FindInstance can find all the solutions over a given range of parameters

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Immy Salam's user avatar
1 vote
0 answers
60 views

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. ...
user66834's user avatar