Linked Questions
11 questions linked to/from How to eliminate variables when using Solve[]
0
votes
1
answer
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A specific usage of "Solve" function [duplicate]
It is something from Simplifying polynomials with conditions on variables, that intend to minimize the number of variables.
The problem is the usage of ``Solve". I know how to solve equations, ...
- 115
211
votes
24
answers
17k
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What are some useful, undocumented Mathematica functions?
There have already been some questions about some undocumented functionality in Mathematica. Such as (please add to these lists!)
How can one find undocumented options or option values in Mathematica?...
18
votes
2
answers
2k
views
Behavior of Reduce with variables as domain
When using Reduce, I accidentally put a set of variables as the domain. To my surprise, it not only seems that Reduce expects ...
- 1,752
4
votes
2
answers
335
views
Rewriting algebraic expressions as combinations of other expressions
I would like to write x^5 + 1/x^5 in terms of x^2 + 1/x^2, x^3 + 1/x^3 and ...
- 219
1
vote
1
answer
465
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How to speed or help Solve[] when it is stuck?
The code below generates a system of equations that I need to Solve[] for {c[5], c[6], c[7], c[8]} in terms of {c[1], c[2], c[3], c[4]}.
...
- 4,553
3
votes
2
answers
131
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Arrange a system of differential equations to standard state-space equation form
I want to model an electrical circuit in the form of state-space equations, and I want to use Mathematica to solve the final equations, the circuit equations (from Kirchhoff's law) are shown below, ...
- 45
1
vote
1
answer
107
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Expression substitution
I konw:
$$
a_0=\frac{4 \pi \epsilon_0 \hbar^2}{m_e e^2}
$$
and
$$
\alpha = \frac{m_{\mathrm{e}}^2 e^4}{18 \pi^3 \epsilon_0^2 \hbar^4}
$$
So we can use $a_0$ for $\alpha$,like this:
$$
\alpha=\frac{m_{\...
- 1,402
4
votes
2
answers
152
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Simple symbolic parametric differential equations
I'm relearning Mathematica after a long time away, and trying to remember how to do some things best.
At this point, I'm trying to evaluate $\frac{dy}{dx}$, given:
$$
\begin{align}
y&=\frac{3}{t}\...
- 476
1
vote
1
answer
197
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0
votes
2
answers
172
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solve nonlinear differential equations for some variables [closed]
I have a few nonlinear differential equations and some variables that I need them to be eliminated when I am calculating differential equations based on other 3 variables, but I can just get an answer ...
- 159
1
vote
2
answers
52
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Solving simuntaneous equations with elimination of a variable [closed]
I have the following relations:
Dc == k*t0^2
Dp == k*t1^2
I know that I can do the following:
$\qquad \frac{D_c}{k\space t_0^2}==1
\quad \frac{D_p}{k\space t_1^...
- 1,560