Questions tagged [simplifying-expressions]
Questions on manipulating complicated expressions and making them look simpler using Simplify, FullSimplify and Reduce.
1,853
questions
1
vote
1answer
54 views
Understand a result of FullSimplify
FullSimplify[((Sqrt[5] - 1)/(2*2^(1/4)))*Sqrt[Sqrt[2]*5^(1/4) - Sqrt[Sqrt[5] - 1]]]
returns
...
0
votes
0answers
19 views
Mathematica does not make obvious simplifications using Feyncalc
Just recently, I got introduced to the FeynCalc package and in order to really understand how it works, I decided to try and re-compute the Feynman Propagator of a normal QFT (without using FeynCalc's ...
0
votes
0answers
35 views
Simplify is giving wrong result in Mathematica [closed]
I am trying to do a simple multiplication of variables in Mathematica:
Simplify[n*(n + 1)*(n + 2)] /. {n -> 6*p + 1}
This gives me the output:
...
1
vote
2answers
51 views
Approaches to expression reduction
I am still learning how to use Mathematica more efficiently, but something that I keep bumping into is problems with it reducing formulas. Often, I'll ask it to compute a certain formula (take a ...
0
votes
0answers
31 views
How to express sum of rational functions as a single term [closed]
I have rational functions $\dfrac{q_1(x)}{p_1(x)},\ldots,\dfrac{q_n(x)}{p_n(x)}$ whose numerator I am trying to compute.
I want mathematica to take the lcm of $p_1(x),\ldots,p_n(x)$ and express the ...
0
votes
0answers
31 views
Converting Tensor product to Matrix
I have a basic question regarding matrices and tensor product forms. Given $N > 0$, I am interested in the tensor product series $\sum_{i}^{N} X_i$, where $X_i$ is the Pauli $X$ spin operator at ...
0
votes
1answer
28 views
Perform Eliminate, Solve and Format at once in Mathematica
I have a series of equations where I use eliminate to get a new equation with desired variables. This equation is then solved for a specific variable and then the result is presented in a specific ...
1
vote
1answer
72 views
How to simplify the following integral to be in terms of Bessel functions?
I have evaluated the following integration using Mathematica. I obtained a solution in terms of Meijer G function. I wonder if it can be simplified to be in terms of Bessel functions.
...
4
votes
1answer
109 views
How to show these two expressions are the same?
I think
Can be simplified to $-x^2$
I tried Reduce, FullSimplify, FunctionExpand, and ...
0
votes
2answers
67 views
Create my own 'Refine' function
I'd like to understand how the Refine function works internally.
I tried to create my own Refine function to support basic cases,...
3
votes
3answers
87 views
Simplifying a expression containing an even function
I want to simplify a expression with a even function Df[x] == Df[-x]
...
-3
votes
1answer
58 views
How to simplify equation in Mathematica? [closed]
I would like to know how can I simplify the following:
in Mathematica.
14
votes
4answers
526 views
Why MMA refuses to simplify the following simple expression?
I have the following simple expression
Exp[(Log[1 + x]^2 - Log[x]^2)/Log[1 + 1/x]] - x^2
that can be shown to simplify to x for ...
2
votes
1answer
67 views
Expression conversion to a sum of base-N
I have: 1/(2^(1/2) - 2^(1/3))
And would like to dissolve the denominator and convert it to sum of numbers in the form 2^q where q is Rational.
Does Mathematica ...
0
votes
1answer
41 views
How to solve three simultaneous equations on Mathematica to get N in terms of X,Y and Z?
I am trying to solve a system with 3 equations 3 unknowns. My code is following
X = A1*S + N1
Y = A2*S + N1
Z = N1^2 + A1N1S + A2N1S + 2A1A2*S^2
2
votes
0answers
97 views
3
votes
1answer
81 views
Simplifying Floor/Ceiling expressions
I'm working with symbolic expressions using Floor and Ceiling, and I'm unable to get Simplify...
1
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0answers
40 views
dot product of vectors with noncommutative elements
I came upon an interesting problem. Suppose you have three vectors $\psi=(a, b)$, $\phi=(c,d)$ such that their components do not commute:
$ac\neq ca$, $bd \neq db$ etc.
(in general the vectors may ...
1
vote
1answer
52 views
function within function
delFunc[funcform_, lstofparams_,lstoferrs_] := āTotal[Table[(D[funcform, lstofparams[[i]]]*lstoferrs[[i]])^2, {i,Length[lstofparams]}]]
...
0
votes
1answer
57 views
simplifying indefinite sums containing Kronecker Deltas
I want to simplify indefinite sums containing KroneckerDeltas, e.g:
$\sum_{k,k1,q} \beta(q) \beta(k+k1+q) \delta(k1+q)= \sum_{k,q} \beta(k)\beta(q)$ where $k,k1,q \;\epsilon \; \mathrm{R}$
...
2
votes
3answers
104 views
FullSimplify doesn't simplify enough
In 12.1.0 for Microsoft Windows (64-bit) (March 14, 2020), writing:
...
-1
votes
0answers
48 views
How to see the close form of special polynomials in mathematica?
Is there any way to decompose a polynomial (for example $x^2+2x+1$) by using an identity ($(x+1)^2$)?
Moreover, it could be interesting to know this command for other mathematical identities. For ...
0
votes
0answers
34 views
Simplifying expression involving Boson operators
I want to do calculations involving Boson operators $a(k), a^{\dagger}(k)$, e.g $(x + a(k))(y+a^{\dagger}(k))$. My code is:
...
0
votes
1answer
65 views
Simplify and solve an N-term exponential equation
How does one express this sum into Mathematica:
$$10^{k-1} + 10^{k-2} +....+ 10 + 1$$
I think I have to use the Sum function? Then run it over N=K..1? But then I want to substitute and evaluate it for ...
0
votes
0answers
29 views
summation involving Kronecker Deltas
I see that:
Sum[u[q] u[k] v[k1] v[k + k1 + q] KroneckerDelta[k1 - q], {k1, -\[Infinity], \[Infinity]}]
produces the correct result: ...
1
vote
0answers
47 views
Simplifying an expression involving square roots
Consider a minimal example:
FullSimplify[Sqrt[2/15 (7 + 3 Sqrt[5])]]
This will turn out nothing. On the other hand, the expression can be indeed simplified, since
<...
2
votes
2answers
63 views
RecurrenceTable is not honoring FullSimplify
I define a function nextK and compute the first three terms in a recurrence as follows:
...
0
votes
2answers
70 views
Simplifying expression involving Trignometric functions
Mathematica is not simplifying the following function. I have tried TrigExpand, FullSimplify, etc. Nothing is working.
...
0
votes
0answers
30 views
Simplify the coefficient of an expression after calling Collect
I have an expression for which I have run Collect to get the expression in terms of a few variables. I now want to run Collect ...
0
votes
0answers
25 views
How to stop Mathematica from using polynomial relations to simplify expressions
I am making a table whose entries involve Jacobi polynomials, $P_n^{(\alpha,\beta)}(x)$. Each entry contains some expression polynomials as a function of $n$, i.e. the first entry will be some ...
2
votes
2answers
56 views
Solve for two variables but output second variable in terms of first variable
Here are some equations for illustration:
Format[Solve[{4*r1^3 == r2^2*(3*h),
t*r2^2*(h - d) == r2^2*(h + d)}, #] & /@ {{h, d}}, InputForm]
Here is their ...
1
vote
0answers
126 views
Simplify trigonometric functions to take the Laplace transform
I have one trigonometric function which is simplified as
f[t_, RV_, H_] := 0.000308148 H Cos[0.172439 RV Sin[2 \[Pi] t]]
It is an input to one ODE which I want to ...
-1
votes
1answer
57 views
Combining multiple graphs in one photo without consulting external programs [closed]
I want to add many plots from Mathematica into one picture and export as a PDF. Usually I select the plot and copy it as an image to Word, however the image reduces the accuracy of some plots.
How can ...
0
votes
0answers
32 views
Evaluating functions at particular points
I'm a beginner with Mathematica, and I'm running into an issue that I don't quite understand. I define the quantities
denom1 = (Sqrt[k^2 + m^2] - p)^2 - k^2 - m^2
...
2
votes
0answers
71 views
Need help with symbolic tensor calculus using Kronecker products
I am quite new with Mathematica. I need to do symbolic tensor calculations but what I try does not seem to work. I have found similar questions to mine, but I need a generalization
Specifically, if <...
1
vote
2answers
33 views
How to help Simplify with conjugates without using ComplexExpand
I have a seemingly simple simplification involving conjugates:
$Assumptions = Element[{a}, Reals];
FullSimplify[ x E^(I a) + Conjugate[x] E^(-I a)]
which merely ...
2
votes
0answers
49 views
Trigonometric Simplification and Double Angle Formula
I am trying to achieve the formula hbar / 2 * cos(wt) * sin(theta). However, my Mathematica expression doesn't seem to simplify the half/double angle formulas. I am ...
1
vote
1answer
44 views
How to put numerator and denominator in a canonical form?
I have the following expression that I obtained after some computation:
...
1
vote
0answers
42 views
Reading product of same ByteArrays
I am handling a huge set of data and I am trying to optimize my code. I have very large expressions to expand and simplify and I've seen that converting the expressions to ByteArrays improves a lot ...
0
votes
0answers
42 views
Simplifying elements of a matrix
These elements of the matrices can be simplified by hand much further{roots can be cancelled and all}, yet the Fullsimplify in Mathematica doesn't simply it completely.
The matrix is:
...
0
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0answers
35 views
Exponential simplification in Refine, Simplify and FullSimplify
These lines are the MWE of a bigger script
...
2
votes
1answer
67 views
How to prevent TrigReduce auto evaluating Sin and Cos
Mathematica automatically evaluates Sin and Cos when TrigReduce is applied. For example, <...
2
votes
0answers
43 views
FullSimplify not working
\[Phi]=\[Pi]/8
G=Cos[\[Phi]]*M+ I*Sin[\[Phi]]*N
In the answer to the above code I am getting an answer without any reduction as follows
I have tried ...
0
votes
1answer
45 views
How do I give assumptions to Simplify or Solve? [closed]
I've have the expression:
q2sol =
(Sec[2*a1]*Tan[a1]^3*(-7 + 6*Cot[a1]^3*Sqrt[Tan[a1]^2]))/(6*Sqrt[Tan[a1]^2])
I know that a1...
1
vote
1answer
41 views
Using FullSimplify to simplify an expression with assumptions
I am working with Poisson brackets of Angular momentum, and I want Mathematica to be able to return the angular momentum function if the Poisson bracket yields that result. I.e. provided
...
0
votes
0answers
46 views
Making a equation smaller and more readable by using another variable [duplicate]
I am deriving an expression and the output of it is a very long mathematical expression. I want to minimize the equation by substituting some other variables. For example:
This is just an example ...
0
votes
1answer
38 views
1
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0answers
38 views
How to change behavior of Echo or turn it off without removing it from code?
I wish to use Echo for output of intermediate results if an OptionValue I call ...
1
vote
0answers
61 views
Problematic matrix calculation [closed]
I have defined matrix as such
u1 = {0, I, 0, 1};
u2 = {I, 0, 1, 0};
Ī»1 = Sqrt[m/2] (u1 + (I*u2));
Now I define the matrix multiplication with $ 4\times 4 $ matrix ...
2
votes
1answer
49 views
Find values of n for which expression is integer
I have an expression for which I want ot find values of n that will make it an integer. Here is the expression:
(n^(3/2) - n)^(1/3)
or
n^(1/2) - n^(1/3)
I want to ...
