Linked Questions

2
votes
1answer
312 views

How to Collect $x$ powers to group $\sqrt{x}$ and $\sqrt{1+x}$ together?

I have been failing to apply Collect[#, x]& to render a like-power series of $x^k$. Here $k = \frac52, \frac32, \frac12,\frac{-1}2$, etc. The major issue is: ...
1
vote
1answer
310 views

Writing a trigonometric expression in terms of another [duplicate]

This is related to another question, in which one wants to rewrite a function of a single variable in terms of another function of that variable. Here I have a function of multiple variables. I want ...
2
votes
1answer
200 views

Substituting variables inside a matrix

I'm trying to substitute some dependent variables into equations inside of a matrix, however $Replace[]$ and and $/.$ don't seem to work. The equation in question is just a vector matrix of ...
0
votes
3answers
153 views

How to simplify an expression by substitution?

Sometime Solve and DSolve give a finial form of the solution, which is fine in may applications. However, in some cases, one may ...
1
vote
3answers
153 views

Substitution in expressions

As the title suggests, I want in an expression to to some substitutions. For example in the expression $\mathcal{L}^+_0+\mathcal{L}^-_0+\mathcal{L}^+_0+\mathcal{L}^-_0+\mathcal{L}_1$ I want to ...
1
vote
0answers
229 views

How to simplify expressions

I read several similar posts but I have not found a solution yet. However, I think that my problem should be quite easy. So here we are. Relations ...
3
votes
1answer
132 views

Replacing patterns (determinants) in a rational multivariate function and/or getting `replacementFunction` to work on a multi-linear expression

Given a rational multivariate function known to contain determinants, what is the best way to rewrite the function in terms of the determinants? A simple example: ...
3
votes
2answers
95 views

Treat 2 variable as 1

Is there anyway to treat two variable, that are a result of expansion, as one? To use Solve[] I can do ...
1
vote
2answers
81 views

Applying a simple transformation rule when Plus automatically simplifies

I have the following simple rules: {x2-x1->s1, -(x2-x1)->-s1, x3-x2->s2, -(x3-x2)->-s2} I want to apply that rule to the following: ...
1
vote
0answers
141 views

How to Pattern Match complicated patterns? [closed]

How can I get the output expressed in terms of p1 and p2 instead of exponentials? ...
1
vote
0answers
94 views

How does PacletInstall work? And is it possible to find packages using PacletInstall?

It seems that many packages published could be installed using PacletInstall . For example, from this Rubi install instruction webpage, we could see the comman: ...
2
votes
1answer
50 views

Replace subexpression that appears as inverse too

I have eq=Sqrt[(g m)/h] Tanh[Sqrt[h/(g m)] t] then I am trying to replace Sqrt[m g/h] by a symbol ...
0
votes
0answers
63 views

Assign a variable to an expression in Mathematica

I have the following matrix {{a^2 + b + \[Sqrt](m + n) + 5, 23 x + 7 a}, {14 b, a^2 + b + \[Sqrt](m - n) + 5}} I want to replace the expressions ...
0
votes
0answers
63 views

Problem with replacing products involving identical variables due to the rewrite to powrs

This is most easily explained with an example: Say I have a b^2 or a b a and I want to replace ...
0
votes
1answer
59 views

Is there a way to use identities in Mathematica efficiently? [duplicate]

Imagine I have defined a variable l=p/(a*b) Let's say I perform some operations, and I get the final answer to be p/a. But all I ...

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