# 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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### How to find the roots of a transcendental equation that depends on Bessel functions? [duplicate]

I am very new in wolfram mathematica, so i am having trouble in trying to find the roots for this transcendental equation. I am looking for roots of m. Acctually the first non zero value for m. Here J ...
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### Solve a system of differential equations

How to solve this system of equations?
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### How to solve the differential equation

I need to solve the differential equation DSolve[{(1-x)y''[x]==1/5 \[Sqrt](1+y'[x]^2),y==0,y'==0},y[x],x] but the result given seems to be incorrect and ...
16 views

### How to solve an equation by substituting possible solutions? [duplicate]

I wish to solve this equation for kappa, given a certain set of parameters (m and beta): ...
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### Help me factor this equation

I have the following equation: $$\frac{2\left(a A_3 r + \frac{1}{2} r^2 a'^2 \right)}{a^2 r^2}=\frac{8 G \pi \rho}{3}-\frac{c^2 k}{a^2}$$ ...
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### Implementation of the general solution of Abel differential equation of the second kind in Mathematica

Introduction An Abel equation of the second kind in its canonical form is writen as $$y(x)y'(x)-y(x)=f(x)\quad (6)$$ for arbitrary $f(x)$. Despite the fact that this equation has general solutions 1 ...
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### Mathematica does not solve system of equations

I am trying to solve a system of 7 equations and 7 unknowns given a set of assuptions. I am only interested in obtaining V1 as a function of the exogenous parameters. I am using the following code: <...
39 views

I have a two-variable function f[x_, y_] == 0, with a discrete domain for each variable, $x=\{1.5,\; 2.5,\; 3.5,\;4.5,\;5.5,\;\text{...},\infty \}$ and $y=\{0.1,\;... 1answer 57 views ### Root finding: Is there no bisection method root finder? I am trying to find a root to an equation f[k,...]==0 numerically, where k is the variable I am solving for. Using both NSove as ... 0answers 99 views ### Is it possible to solve this equation analytically? I have this equation, and I want to find an exact solution for$x$in terms of$y$. I mean I want to obtain something like$x=f(y)$. Is it possible to solve this equation analytically by Mathematica? <... 2answers 63 views ### How to find non-trivial of a system of equation? I have a system of four equations ... 1answer 131 views ### How can I reduce timing to solve this equation? I am tring to solve equation $$\frac{2 \log (x y+2021)}{\log (2)}+4^{x+1}=2^{x y+2022}+\frac{2 \log (2 x+1)}{\log (2)},$$ where$x$,$y$are integer numbers. I tried ... 2answers 43 views ### Evaluate with numbers from list This code works: x=2 y/.Solve[y==x^2] Out= 2 Out= {4} So above I put number in variable x and getting the result of ... 4answers 121 views ### Is it possible to get a symbolic or numeric relation when solving a transcendental equation? [closed] Here is the code. Solve[(1 - E^x + (3 x^2)/2)/(2 x) == a, x, Reals] Unfortunately, Mathematica told me that this system cannot be solved with the methods ... 2answers 89 views ### How can I solve$\coth (2 x )=x $? [duplicate] I have this equation $$\coth (2 x )=x$$ and I want to solve it to find$x$. The methods Solve and Reduce do not work. Coth[2 x] == x 0answers 39 views ### How to deal with unknown variables in NSolve? I am trying to solve these equations by using NSolve and want to plot$p1^{2}+p2^{2}$v/s P0. But there is some problem, it is showing running... but not showing any error. I don't know where I am ... 1answer 69 views ### Why mathematica does not solve the equation$x\left \lfloor x \right \rfloor=10$for$x$? The equation$x\left \lfloor x \right \rfloor=10$has a real solution, which is$x=\frac{10}{3}$. But when I type Solve[x*Floor[x] == 10, x] a message comes: "... 1answer 167 views ### How to solve system of PDE's with complicated initial and boundary conditions I am trying to solve the Cavity problem given in Paper by Mansour et al. with a physical model . System of PDE and B.C are . How can I impose boundary conditions like this? Code ... 1answer 38 views ### how to solve a quadratic diophanic equation on integers and obtain various results This quadratic di equation has more results, as it came to them. I can only think of this FindInstance[(4 p + 3 q - 2) (p - 1) == (6 p + 2 q) q, {p, q}, Integers] ... 1answer 39 views ### Find the condition under which an inequality holds I've got an inequality of 8 non-negative parameters (arising from a 5x5 matrix) and would like to find a condition under which my inequality holds. The condition would be an inequality too of these ... 1answer 32 views ### why mathematica Holds the Solve on the set of equations in the diagonal a matrix? Say I have a simple function F[x_, y_, z_, r_, a_, b_, c_, d_] := (1 - a + b - (b/3) (c x + d (y + z + r))) x And I want to solve the set of equations given by: <... 1answer 53 views ### Find non-unique Hermitian solution to pair of matrix equations This is a continuation of my previous question here, but I previously did not fully specify some of the restrictions on the matrices and so the solutions posted there were not that helpful. I'm ... 1answer 104 views ### two tier compound interest problem I am trying to make sense of how mortgage repayment figures are calculated for two tier mortgages, where you fix your interest rate for a certain period and after that period, you fall back to the SVR ... 1answer 31 views ### Get Solution range of NSolve I have a numerical solution and when I solve it with NSolve, and substitue the results in an expression, I get something like: 1 + x + x^2 if 0 < x< 10 I ... 1answer 75 views ### Solving Inequalities using Mathematica How can I solve this inequality using Mathematica? Sqrt[B^2 + J^2] Cosh[(2 J)/T ] < J Sinh[ (2 Sqrt[B^2 + J^2])/T] where T, J, and B are reals and they are >... 3answers 80 views ### How to solve these complex equations for plot? I am trying to Plot this code but it is not showing any plot. I want a bistable type plot between "NL" and "P0" and there are six equations and six unknowns. The code is given ... 1answer 52 views ### Problem of Encountered non-numerical value for a derivative at t == 0 I try to solve this equation numerically : eq= z''[t] + (2691+ D[Log[Abs[z'[t]^2]],t]) (z'[t]^2 + Abs[z'[t]]^2 ) == 0; By ... 3answers 148 views ### Verify an inequality of many parameters I've got an inequality of 10 non-negative parameters (arising from a 5x5 matrix) and would like to verify whether it holds. I tried the following, which doesn't seem to work: ... 2answers 126 views ### Underdetermined system of equations Could anyone help me solve this probably simple equation? ... 1answer 106 views ### Solving symbolic system of non-linear equations takes too long I am trying to solve a set of system of symbolic non-linear equations: ... 1answer 41 views ### How to solve all the solutions of this restricted system of equations? The system of equations is as follows: ... 1answer 98 views ### Problem with NDSolveValue : “The function value {$Failed} is not a list of numbers with \ dimensions…”

I was having fun modifying a code given to me as an answer to a previous problem here, courtesy of user Alex Trounev (Thank you again), when I encountered a certain error which I had never seen before....