Questions tagged [equation-solving]
Questions on the analytic and numerical equation solving functions of Mathematica (Solve, Reduce, NSolve, FindRoot, DSolve, RSolve, etc.).
6,863 questions
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Solving a coupled 2nd order differential equation numerically using NDSolve
I would like to solve the following system of differential equations numerically for two one-dimensional functions $R(x)$ and $\phi(x)$:
\begin{eqnarray}
c_1 \left(R''(x) - (\phi'(x))^2 R(x) \right) - ...
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The heat conduction equation of solar cells can't be solved [duplicate]
The heat conduction equation of solar cells can't be solved. NDSolveValue::ndnum: Encountered non-numerical value for a derivative at x == 0. ...
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Mathematica does not give me any contour here
I would like to have an idea what kind of curbe is being formed from the intersection of the plane $x+y+z=9$ with the surface
$\sqrt{16-x^2}+\sqrt{25-y^2}+\sqrt{36-z^2}=12$ under the restriction $x,y,...
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How to find x ranges where a function is one-to-one and its output is in a given range?
I have a list of functions like this:
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The general solution from Solve does not simplify to the specific case
I am trying to get a solution of equation with many parameters. The general solution does not seem to reduce to a specific one.
The specific solution with all parameters known is
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How should we formulate angle geometry constraints in Mathematica to help the solving system work more efficiently and speed up the solution process?
Quadrilateral $ABCE$ is a parallelogram. Point $D$ lies on segment $AE$. The diagonals of quadrilateral $ABCD$ intersect at point P. If $△ABP∼△CBD$ and $AB<BC$, find the ratio $\frac{AB}{BC}$.
The ...
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Are there any good ways to improve this code so that it can solve the geometry problem？
While using Mathematica to solve the following geometry problem, my computation has been running for a long time without producing any result.
The geometry problem is:
Quadrilateral $ABCE$ is a ...
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How can I add inequality constraints to Solve? [closed]
How can I add constraints to the Solve function?
For example, I tried:
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- 1,417
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Parameter search problem for satisfying an inequality
I am working with a $2 \times 2$ matrix
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Using symbolic expression in Compile
I found a Mathematica notebook on the internet, which calculates the inverse kinematics of a 6DoF robot.
link to the notebook
In one part of the code it gives a symbolic expression using the Solve[] ...
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Symbolically solving a set of three-variable nonlinear equations fails to get a simplified result
I want to use Solve to find symbolic solutions of the following set of equations and get simplified or factorised symbolic solutions. The equations are
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How to make DSolve obtain this solution to this IVP first order ODE?
V 14.3 can not solve this IVP(Initial value problem) first order ode from textbook
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Using the Solve function appropriately
I will discuss the background of this problem first. I have an automated code, which solves linear equations recursively. The number of equations could be of the order of thousands. And, more ...
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Why is the Backsubstitution not working in Reduce in this case?
In the following system why is the Backsubstitution not working:
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