Questions tagged [simplifying-expressions]

Questions on manipulating complicated expressions and making them look simpler using Simplify, FullSimplify and Reduce.

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2
votes
0answers
27 views

Compare 2 expressions with variables

I want to check if two expressions are equivalent with Mathematica. For example, is $2 x + 4 + 2$ equivalent to $2 (x + 2 + 1)$. I tried the === operator, which I ...
1
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1answer
44 views

Exploit bilinearity of KroneckerProduct symbolic calculations and inconsistence (apparently)

Mathematica 10 recognizes the bilinearity of the trace and the Kronecker product, as well as Tr$\otimes$Tr$(A\otimes B)=$Tr($A$)Tr($B$). But I have issues trying to implement this in symbolic ...
1
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1answer
24 views

Simplify Difference of Conjugate Pairs

Is it possible to easily simplify the difference of conjugate pairs? In particular, if there's just a single variable, then FullSimplify[a - Conjugate[a]] ...
0
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1answer
40 views

Simplify Jacobi Polynomials

How can I force Mathematica to use the identities satisfied by Jacobi polynomials $$ (1-\cdot)P_n^{(\alpha+1,\beta)} = \frac{2}{2n+\alpha+\beta+2}\left((n+\alpha+1)P_n^{(\alpha,\beta)}-(n+1)P_{n+1}^{(\...
7
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1answer
391 views

Why does Mathematica give exact solution 0 for this indeterminate expression?

I have this function: $\frac{(1-\cos (\theta )) \sin (n x)}{\pi (-1)^{n+1} \cos (\theta )-\cos (\theta ) \cos (n x)+2 \pi \cos (n x)+\cos (n x)+\pi (-1)^{n+1}},$ and I want to know its value for $...
2
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3answers
111 views

Turning numbers embedded in deeply nested lists into strings [closed]

This must have a simple answer, but I cannot think of it. I want to take the numbers in a list such as: {1,{2,{{3,4},{5,6}},7,8} into strings. ToString will turn the whole list into a string. ...
0
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2answers
30 views

How do you simplify a boolean expression (!A B)+(B !C)+(BC)+(A !B !C)? [closed]

How would you simplify the following boolean expression (!A B)+(B !C)+(BC)+(A !B !C)? I factorised B and managed to get B(!A+!C+C)+(A !B !C) = B+(A !B !C), but I do not know where I should go next. ...
2
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3answers
82 views

Finding the value of an expression [closed]

Here is an expression that can be easily shown to equate 2 by analysis. $$\sqrt[3]{7+\sqrt{50}}+\sqrt[3]{7-\sqrt{50}}$$ But no matter what i try Mathematica always shows a complex result:2.62132 + 0....
3
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1answer
76 views

Is there a way to force Mathematica to collect terms in a more readable way?

I've got the following result from an operation in Mathematica: ...
4
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1answer
56 views

How do I extract just a part of an expression?

I have the result of an operation: ((t0M^2 + t1M^2)*xC/(2*t0M^2) What is the best way to get just the $\frac{t0^2+t1^2}{2\space t0^2}$ from this expression? This ...
-1
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1answer
43 views

Simplifying complex expresion (without ComplexExpand or User defined rules) [closed]

Many times, I've struggled with simplifying complex expressions, such as this extraordinarily simple expression, and Mathematica wont do it: ...
0
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0answers
49 views

How do I define if two variables are equal to each other

Let's say I have the function x + y = z and I know that x = y. How can I define this in Mathematica? I tried using ...
4
votes
1answer
86 views

A pattern replacement to force Mathematica to replace inexact 0 multiplication by zero

Hi Consider the following expression which contains multiplication by inexact 0 ...
1
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0answers
63 views

Why doesn't Mathematica simplify? [closed]

Consider the following: Simplify[Integrate[x^(a), {x, x1, x2}], x1 > 0 && x2 > 0 && a > 0] Mathematica doesn't simplify this for me. I ...
0
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0answers
53 views

How to deal with complex equations in Solve method?

I am trying to deal with complex equations to solve them and use them in the plot. I want to know why these equations are not being solved. ...
1
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1answer
42 views

Is there any way to prioritize Gamma function?

In Mathematica, if you type Gamma[1, 0, -a] It automatically simplifies to 1 - E^a. I wonder though if there is a way to stop ...
4
votes
0answers
41 views

Force Solve to respect unit system

I give Solve quantities in FPS and it returns resulting quantities in SI, necessitating that I add an entire section to my workflow where I pick apart the solution ...
3
votes
1answer
104 views

Simplifying algebraically

Is there a way to derive an simplified expression from other equations. Or create an alternate form such that the main equation takes other equations and manipulates the main function. Here is what I ...
2
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0answers
25 views

Computations with OptimizedExpressions without completely expanding them

I have to manipulate huge expressions that are rational functions of many (∼30) variables with integer coefficients. Storing them just as a ratio of two polynomials would be impractical. But they can ...
1
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0answers
33 views

Group parameters that only occur together [duplicate]

I have a long and complex univariate expression with many parameters, $ f(x; a, b, c, d, ...) $. I would like to group those parameters which only ever occur together. Here is a very simple example ...
1
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1answer
27 views

Simplify expression with abstract matrices

After defining a commutator function Commutator[X_, Y_] := X.Y - Y.X; I would like to be able to simplify abstract matrix algebra expressions such as ...
4
votes
1answer
59 views

How to Force the PolyGamma[0, x] function or the HarmonicNumber[ x ] function

I'm crunching some infinite summations, and sometimes Mathematica generates results that have the PolyGamma[0, x] function (which is the Digamma) and sometimes the <...
1
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1answer
38 views

Simplify terms with delayed and immediate function definitions

Say I want to define a function fwith input x but also involving parameter p not yet ...
2
votes
0answers
74 views

Why aren't radians dimensionless?

α = Quantity[-3, ("Radians")/("Seconds")^2]; ω = Quantity[-4, ("Radians")/("Seconds")]; r = Quantity[2, "Feet"]; at = α r an = ω^2 r a = Sqrt[an^2 + at^2] ...
1
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0answers
54 views

Simplification of expression with sum of absolute values

I try to simplify following expression 1/2*(Abs[a1] + Abs[b1] + Abs[c1] + Abs[d1]), where a1, b1, c1, d1 are quite long: ...
1
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1answer
37 views

Mathematica reduces domain when simplifying function

This question was initially (wrongfully) posted on Mathematics SE. I have the following expression: $$ \sqrt{1 + 10^{\frac{rdb}{10}} + 2^{1 + \frac{rdb}{20}} 5^{\frac{rdb}{20}} \cos(\mathrm{pdiff})} ...
1
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1answer
84 views

How to calculate unknown function in a equation analyticaly? [closed]

I want value of u1 in terms of T1. How i will be abel to do this? ...
1
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1answer
43 views

Reverse substitution [duplicate]

If you apply rules and then simplify you may get something like. (25 A^2 hbar Sqrt[π])/Sqrt[hbar m w] How would you get mathematica to rewrite this in terms of E ...
2
votes
1answer
37 views

Why does ReplaceRepeated work differently in numerator and denominator?

I'm confused about the behavior of ReplaceRepeated. ReplaceRepeated[a Sqrt[b], Sqrt[b] -> c] gives the expected (* a c *), ...
1
vote
1answer
70 views

Pochhammer Simplification

Assumption:: m and n are integers and greater than zero. $Assumptions = {Element[m, Integers] && m >= 0, Element[n, Integers] && n >= 0} ...
4
votes
4answers
320 views

Simplifying this long expression

I have this piece of code, that outputs expression c. ...
0
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0answers
19 views

Running out of memory when expanding an symbolic expression using rules.How to handle such cases?

while deriving equations related to dynamics of 6 connected body, I ended up creating about 3000 set of rules,because of which final expression looks simple, now the issue is when i want to ...
0
votes
0answers
37 views

Assumptions behavior in Refine[Sin[n Pi/2]] [duplicate]

I don't understand why this first expression returns a correct result: In> Refine[Sin[n Pi/2], Element[n, Integers] && Mod[n, 2] == 1] ...
0
votes
1answer
38 views

Why does restricting the domain not eliminate this solution?

Beside this specific problem I'm wondering if there's a more explicit way that I can understand when Solve and Reduce will find solutions. I find myself repeatedly getting stuck where I'll get ...
0
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1answer
65 views

How to verify an inequality?

I'm working with an expression that seems to be non-positive, but I'm having a hard time verifying it: ...
0
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2answers
39 views

Assuming a root and simplify

I want to simplify an expression assuming a given value is a root. Say s[v] is a root of f[x,u]-f[x,v]. Sometimes Assuming works, for example, ...
1
vote
0answers
55 views

Help with double pendulum equations

I'm 16 and I'm pretty new to Mathematica. I've been working on a personal coding project which has some funky maths in it and I am kinda struggling. I've solved for the 4 polynomials but they answers ...
4
votes
6answers
330 views

Simplify or rules don't work with square roots

I am trying to simplify a complicated expression and neither Simplify nor rules are working for me. Here is a very basic example of what I am trying to do: ...
2
votes
3answers
74 views

Why Mathematica doesn't simplify this multiplication?$c^{-L} (c r){^L}$ [closed]

Why Mathematica doesn't simplify this multiplication? I don't know Mathematica it can or not? Please accept my ignorance :) c^-L (c r)^L
0
votes
1answer
25 views

Reducing and finding the magnitude of complex functions

I am very new to Mathematica and I've been trying to use it to perform calculations with complex numbers. I am mainly trying to find the norm of complex expressions with an unknown variable. For ...
0
votes
1answer
39 views

Exponential function not simplified by FullSimplify?

I'm trying to understand why the first expression doesn't simplify while the second does: ...
1
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0answers
40 views

Are two equations equal

I have a two vector laplacians which have very long equations and I have to verify that they are equal, and doing that by hand would take an hour, I have tried using LHS == RHS, which should print ...
1
vote
3answers
39 views

Simplify Trigonometric Expressions so that they no longer contain specific Trigonometric Ratios [duplicate]

I want to simplify the following Trigonometric expression so that it no longer contains Tan[a] and Cot[a]. How can I do that? <...
1
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2answers
73 views

Collect for nonlinear terms

Is there a way to expand Collect, so that it does not only separate equations by polynomial order, but by general nonlinear functions? For example ...
0
votes
0answers
38 views

Simplification of symbolic vector and matrices representation

I'm new to the Wolfram Language programming and I cannot manage to do the following. I wish to use Wolfram Cloud to simpilfy a heavy vector and matrix expression using symbolic complex vectors (...
1
vote
0answers
53 views

Simplify sufficient to check for infinity?

I have a function, comprising of many functions in its definition, which is being simplified to ComplexInfinity. My goal right now is to check each of the comprising function for infinity. If I run <...
0
votes
2answers
54 views

Reducing expressions to simpler form using a known equality

I generally have a lot of trouble getting Mathematica to produce readable versions of solutions. For example, today, when solving a symbolic system of homogenous ODEs (with boundaries provided as ...
0
votes
0answers
36 views

Gamma and Pochhammer simplification

I want to perform some simplification on Gamma function and Pochhammer symbols. For example, ...
2
votes
0answers
39 views

Why FullSimplify doesn't work when subscript included?

This is OK. FullSimplify[l[t] + r[t], {m[t] == l[t] + r[t]}] But when I add a subscript to l, FullSimplify can not return the correct result. Is this a bug? I will be grateful if anyone can give me ...
4
votes
2answers
68 views

LaplaceTransfrom with time shifting

Hi I'm wondering if there's some workaround to get Mathematica to use time-shifting identities for Laplace and Inverse Laplace transforms. My examples are below. ...

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