Questions tagged [simplifying-expressions]
Questions on manipulating complicated expressions and making them look simpler using Simplify, FullSimplify and Reduce.
1,918
questions
0
votes
2answers
97 views
Quick way to numerically cancel exponentials
I have a problem with exponentials and the use of the commands N and Collect. I am trying to write a code that generates a very ...
0
votes
0answers
30 views
TexForm Simplifies Equation but Holdform Doesn't Work
I have several functions , g1 through gn, that I want to export the LaTeX for. For each iteration of the loop, the function is named gg[x,t]. I want to export the ...
0
votes
1answer
54 views
Solving an equation, and verifying that it is correct
I want to solve the equation
Solve[e == 1/2 (-2 ef + hvk - Sqrt[9 hvk^2 + 4 j^2]), hvk]
I then obtain the solutions
...
1
vote
1answer
32 views
How to simplify an expression, with a given term?
I am trying to simplify the following expression, simply replacing (\[Omega]1 - \[Omega]2) == \[CapitalDelta]:
...
0
votes
0answers
77 views
0
votes
1answer
141 views
Integrate real function returns complex function [closed]
I want to compute the integral
$$
\int_0^c \exp(-cx+x^2) \mathrm{d}x,
$$
where $c>0$ is an unknown constant. In Mathematica Version 12.2.0
...
0
votes
1answer
48 views
Surd factors do not auto cancel each other out
Simplify[Sqrt[Pr] - (Sqrt[Pr/Ra])*Sqrt[Ra]]
The above command should give me 0 as the simplified outcome, but it keeps ...
0
votes
1answer
46 views
Simplification and numerical evaluation differ substantially
My question is very simple. I am trying to simplify an expression that I was expecting to be vanishing. However, If I numerically evaluate the expression (for large values of one parameter) I find 1, ...
0
votes
0answers
47 views
DSolve is returning the same equation
The equation I am trying to solve on Mathematica is programmed as follows:
...
3
votes
1answer
77 views
How to get True for X^2>= 0? [closed]
How to get true when introducing the expression $x^2 \geq 0$ in mathematica ?
how do I specify that x is real ?
GreaterEqual[x^2, 0, Element[x, Reals]]
2
votes
2answers
92 views
Does a positive real solution exist to this problem?
I wrote the following code for getting the solution. I am not sure if the code I wrote is correct. The problem is further intensified by the fact that I don't know if a solution exists to this problem ...
0
votes
1answer
29 views
Real part of a function
How to find the real part of the following function in Mathematica?
The function is $$e^{-i\psi}\langle\beta|\alpha\rangle$$. When expanded, it is given as:
$$e^{-i\psi}\exp\left[\beta^{*}\alpha-\vert\...
1
vote
0answers
48 views
How to best compute the maximum value of a multivariable function?
I'm new to Mathematica. I have the function:
...
0
votes
1answer
45 views
How to find the exponent of Bessel function related infinite integral? [closed]
Please suggest how to find the power law exponent for curvature vs r, I am trying using exponet but it is not working.
...
0
votes
0answers
37 views
Cancel common factors in symbolic product
Suppose I have the following function
G[n_, k_] := Product[g[n + i]/g[i], {i, 0, k}]
where $n,k$ are assumed to be natural numbers and $g$ is a nonzero symbolic ...
1
vote
1answer
35 views
Variable substitution when integrating with Mathematica
When I try to integrate this MMA freezes:
II = (2 fx R Cos[ϕ] Sin[θ])/(R^2 + ρz^2 - 2 R ρz Cos[θ])^(3/2)
...
3
votes
2answers
141 views
Applying the identity $\sin^2 + \cos^2=1$ without any other trigonometric simplifications [closed]
Mathematica does not automatically simplify $\sin^2 + \cos^2 =1$, but applying any kind of trigonometric simplification results in not only that identity being applied but also all kind of trig ...
1
vote
0answers
55 views
Get rid of of $O(\epsilon^2) $ terms [duplicate]
So basically I have the expression on the form:
(4 ϵ^3 a b )/((-1+ϵ)^2 (a-b)^2)
or $ \frac{4 \epsilon^3 ab }{(\epsilon -1)^2 (a-b)^2} $.
I guess this is a math ...
1
vote
1answer
55 views
Mathematica does not simplify divergent integrals
I get this as output:
$\frac{1}{6} \int_0^{\infty } 6 t \, dt$
Why it cannot cancel the coefficients?
1
vote
0answers
27 views
Rearranging an expression for floating point accuracy?
Does Mathematica have the feature of rearranging an expression with the goal of minimizing floating point accuracy errors? I'm asking this because I have some long expressions that really suffer when ...
0
votes
0answers
28 views
Simplifying piecewise function containing symmetric equation terms
I have this large piecewise function that I'd like to simplify (click on image):
I see that two first piecewise equations contain terms that are either completely equal or symmetrical. I would like ...
1
vote
1answer
40 views
3
votes
2answers
102 views
Simplify with function composition
I would like to write an expression of the form $a/\sqrt{b c}$ as $a/d$ where $d = \sqrt{bc}$. My hope was to use a similar strategy as when the square root is omitted:
...
3
votes
3answers
86 views
Simplifying a trig expression
How can I get Mathematica to simplify the following expression?
Pi-ArcCos[-1/Sqrt[3]]
I'd like the answer to be ArcCos[1/Sqrt[3]], which seems manifestly "...
0
votes
0answers
49 views
Reduce : This system cannot be solved with the methods available to Reduce
I have a few expressions and need to get a final simplified (reduced,solved) results. I am new and tried/searched different ways for my problem but couldn't find the reason. These are my expressions:
<...
0
votes
1answer
28 views
How to properly simplify with variable constraints (including infinity)
I'm new to mathematica and have trouble simplifying an expression.
I want to simplify the expression:
Exp[-s*t]
under the constraint that t=+Inf and s is a ...
2
votes
1answer
82 views
Is there a good method for making sophisticated (and terse) code into more verbose code?
For example, this is really nice code, but my first instinct is to make it more verbose so it is easier for a beginner to read:
...
1
vote
1answer
64 views
0
votes
0answers
37 views
How to find out rational exponent
I am trying to check whether an expression has any rational exponent or not.
I am using the following boolean to check that and a combination of Exponent, ...
1
vote
0answers
38 views
A question about simplifying
From basic examination, the following expression
Integrate[Abs[a - x], {x, 0, n}]
appears to simplify fully to
5 n - n a + a^2
...
0
votes
1answer
43 views
Remove specific terms from Mathematica output
I have a very complicated output from Mathematica - which may run to several pages - and I want to keep only some of the terms.
The expression I am working with is a double summation. It results in (...
5
votes
2answers
126 views
How do I write Sqrt[x] as x^(1/2)
Sometimes it is needed to keep the powers as the fractional form. However Mathematica tends to write x^(1/2) as Sqrt[x].
How do ...
1
vote
1answer
35 views
How can I get a matrix valued function to act like a matrix instead of a scalar?
A small example illustrating the issue:
If
p:={{1,0},{0,0}};
q:={{0,0},{0,1}};
a[t_]:=Piecewise[{{p,t<=0},{q,t>0}}];
And I then define
...
1
vote
1answer
31 views
Addition of matrices not working as intended with piecewise definition
A somewhat minimal working example:
I define p:={{1,0},{0,1}}, q:={{2,0},{0,2}}, and finally
...
2
votes
2answers
102 views
Map a function at one “part” of each term in a multivariate polynomial
I have polynomials in several variables x[i] and y[j], and I am using First@SymmetricReduce@ ...
8
votes
2answers
489 views
Simplify 1+Sqrt[2]I-Complex[1,Sqrt[2]]
The expression 1+Sqrt[2]I-Complex[1,Sqrt[2]] should be zero. In fact, N[1+Sqrt[2]I-Complex[1,Sqrt[2]]] yields ...
0
votes
0answers
65 views
Result not simplified
The following script gives not the simplest result. What should be the right command to get the simplest result?
...
2
votes
0answers
61 views
How can I simplify a symbolic tensor expression?
My question is about simplifying tensor expressions. If I have
$(a+b)\otimes (c+d)$
The function TensorExpand gives
$a\otimes c + a\otimes d + b\otimes c + b\otimes ...
2
votes
2answers
118 views
How to check linear independence
I want to check linear independence in Mathematica. But I don't know to how to use this. My question is as follows:
I want to check whether $\sin (m \pi x) \sin (n \pi y)$ where $m, n =1,2, 3 \cdots$ ...
1
vote
0answers
38 views
Binomial Expansion on Mathematica [duplicate]
Why when I typed Expand[Binomial[m-1,6]], it gives me Binomial[-1 + m, 6] instead of ...
3
votes
1answer
94 views
How to Simplify safely
Mathematica often writes simplied expressions with -1 first followed by any variables (eg. -1+x).
However I want to write it as ...
0
votes
1answer
50 views
Integration shows RootSum and really long expressions
I am doing this integration and when I use $C_\alpha(T)$ as just constant numbers(...
1
vote
1answer
68 views
limit of an expression including BesselK function
i want to calculate the limit of the following expression when 'w' tend to zero. I have used the Limit function, it takes a lot of time for running without any result. could you please help me how to ...
5
votes
4answers
312 views
Calculating commutators in quantum mechanics symbolically with the help of Mathematica
Say I have a hamiltonian $H=p_x^2+p_y^2+x^2+y^2+x^4+y^4$, and I want to calculate the commutator $\left[A,B\right] \equiv AB-BA$ of arbitrary operators $\mathcal{O}=x^ap_x^by^cp_y^d$, where $a,b,c,d\...
0
votes
0answers
49 views
Problem in FullSimplify with assumptions:
For the vector $\psi = \{ 0,F1,\alpha ,0,\beta ,0,0,F2\} $, I am trying to simplify ${\left\| \psi \right\|^2}$ where
$\alpha = \cos (\theta )$,
$\beta = \sin \left[ \theta \right]$,
$F1 = {{\cos ...
1
vote
0answers
52 views
Reduce only generically correct?
While it is clearly said in the Mathematica documentation that functions like FullSimplify yield only 'generically correct' results, I have found no mention of such restrictions for Reduce. However, ...
0
votes
2answers
81 views
2
votes
0answers
71 views
How to sum the KroneckerDelta[] in equation?
How to sum the KroneckerDeltas in following equation?
k, p1, ...
1
vote
0answers
71 views
Exponent combinations
How can I have Mathematica represent the product of two different bases and exponents as a single power (where possible)?
For example, see the product below can be expressed below:
...
0
votes
0answers
38 views
How can I use a replacement rule as part of a simplification?
I am using Mathematica to symbolically calculate the likelihood for a simple linear regression model. As part of this I want to substitute
...
