Questions tagged [equation-solving]

Questions on the analytic and numerical equation solving functions of Mathematica (Solve, Reduce, NSolve, FindRoot, DSolve, RSolve, etc.).

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NDSolve::conarg: The arguments should be ordered consistently mistake

I want to solve a system of differential equations, but I get NDSolve::conarg: The arguments should be ordered consistently mistake. How can I avoid that? code: ...
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Solve Laplace equation in Cylindrical - Polar Coordinates

Hey mathematica stackexchange!! I've got a (possibly stupid) problem. I've tried many things to no avail, and I've read every post I've found on Laplace's equation. Background: I'm trying to find the ...
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Solving complex trig quations - missing solutions?

{ Sin[Pi/2 + I*Log[2 + Sqrt]], Sin[Pi/2 - I*Log[2 + Sqrt]], Sin[Pi/2 + I*Log[2 - Sqrt]], Sin[Pi/2 - I*Log[2 - Sqrt]] } // FullSimplify ...
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Defining a big matrix for iterative algorithm

I need to solve this system of equations with Seidel and Jacobi methods, so I tried to define a big matrix in Wolfram. I have read documentation, and I wrote the following command that should help me,...
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FindMinimum giving wrong answer

I have a very simple problem that Mathematica is giving a wrong answer to. I want to minimize the following function: $\frac{3+t^2+6\theta +3 \theta^2}{6 t^3}$ in $\theta$ and $t$. Now, plotting the ...
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How to substitute by NDSolve solution to plot a new function

Assume I got some function by NDSolve , like y(t) ...
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Solve the vector-matrix equation. Minimize the length of the desired n-dimensional vector

There is the following vector-matrix equation. where C - nonzero constant. [x1 x2 ... xn] - vector of real numbers. M - matrix of real numbers of dimension n x n It is required to find a vector $x$...
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Finding the inverse of a function

I am to solve for $r(\rho)$ given the function, \[Rho]Asymp[r_,b_,q_] := 1/(1 - q) Gamma[1/(1 - q)]/Gamma[(q - 2)/(q - 1)] r Sqrt[1 - (b/r)^(1 - q)] This can be ...
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How to solve this equation in Mathematica?

I wonder what is the best way to solve this equation in MA? $$y= \frac{\partial}{\partial x} ~ \frac{\partial}{\partial x^*} f$$ where y and ...
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Trying to to replace Root expressions from the output of Eigenvalues by the explicit forms

When I calculate the eigenvalues of the following matrix (H) by using Eigenvalues, I get complex expressions with ...
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Solving equations with two parameters

There are two equations: Integrate[1/Square(2*Cosh[y] - 2*Cosh[u]) , {y, z, u}] == 0.013 2*Cosh[z] - 2*Cosh[u] == 0.41 How can I obtain z and u?
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Numerically solve system of equations with nested variables

I'm trying to solve the following system of equations. The first two equations depend on the variable TeV ...
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FindRoot with constraint that the variables are not equal

I have this system of equations : ...
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Problem with NSolve with Logarithm

I have an issue with NSolve, and I think it's because of the logarithms : ...
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Solving these equations with a constraint

I have been for long time now try to solve this equation q1[t_] = D[x[t], t, t] - 2 (1/y[t]) D[y[t], t] D[x[t], t] With its complex conjugate ...
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Solving a system of linear equations with a For-loop

I need to find the value of c1, c2, c3, c4 and c5, but the output from my code is the simplified equations, not the exact value ...
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Can Mathematica check ansatz for solutions of differential equations?

I'm just a beginner learning Mathematica. I'd like to do something with it, but I don't know if it is possible. Suppose I want to solve a system of differential equations, maybe a nonlinear one, and ...
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NIntegrate user defined function

I have the the function f[a_] := Module[{solution, ans, x}, solution = NSolve[x + a == 4]; I want to integrate it by writing ...
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Solve system of equations does not match

I have the following system of equations: ...
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Why maple returns nothing on this diff equation? [closed]

I am very new to this software. I have a differential equation, but when I run this code, it gives me back wrong statement of {x} as a symbol variable... What should I specify more on this equation? ...
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Problem in solving a trancedental equation which is embedded in module

I have written a small program to compute the resonance frequency, for that I am solving a transcendental equation, which comes from the determinant of the matrix ...
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Restricting Solve to positive reals

I want to restrict the solutions to Solve to the positive reals. This is my code: ...
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Solving numerically a dissipative non-linear system of coupled ODEs [duplicate]

My problem is to integrate a set of couple non-linear and first order ODEs. They are Eqs. (45) -- (50) in the paper https://arxiv.org/pdf/1901.03380.pdf. This is the set of differential equations I ...
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The difference of Prime in Solve doesn't work

Can someone explain why Solve does not work with Prime difference? This cond does not work: Solve[Prime[n] - Prime[m] == 8, {n, m}, Integers] But you can find ...
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Can't solve for y in a fairly simple work done by magnetic field equation

The equations below are essentially calculations for a railgun-type mechanism (here is a good image description). I also drew an image using my own variables as definitions: I assumed that ...
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Reduce system of nonlinear equations to one nonlinear equation

I have a system of nonlinear equations: ...