# Questions tagged [simplifying-expressions]

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

2,548 questions
Filter by
Sorted by
Tagged with
200 views

### Simplifing equation with complex coefficients

I'm trying to simplify an expression with complex coefficients. It should be very straightforward, but for some reason, I cannot get the correct answer. Please, see the code below: ...
91 views

### Condition on the data of table

If you have a table and want to separate some data into columns according to certain conditions: Let's assume we have the following table: ...
• 982
1 vote
102 views

### Let FullSimplify remove a sum-of-squares demoninator

I am trying to pre-process an ODE system for NDSolve, and the differential equation* have a structure like: ...
• 884
1 vote
65 views

### Mathematica isn't returning identity matrix when multiplying matrix by its inverse [closed]

I'm trying to solve a coupled system of ODE's. I'm trying to decouple my equations by diagonalizing a matrix. Here's my code: ...
1 vote
36 views

### Replacing an expression with pre-defined function

I am asking Mathematica to do a long calculation with functions I am defining at the beginning of the script. Because the resulting expressions are long, I want to replace them with the functions I ...
• 111
51 views

### Expression not clear/ too long [closed]

Wolfram Alpha does not compute anything when I ask it to simplify this: ...
22 views

### "SixJsymbol" function unable to be simplified with long run times due to not real components despite including the assumptions

I'm trying to perform some quantum mechanical calculations using Wigner-Eckhart theorem by running them through Mathematica. However, despite including the assumptions the calculation is unable to be ...
1 vote
64 views

### Max and Transpose in the Probability of a Union

If I have the code that gives the probability of the sum in general ...
• 982
243 views

### How to Series Expand an Expression in Mathematica with Smaller Cross Terms Compared to Diagonal Terms?

I have an expression for E_y in terms of various s terms, and I want to perform a series expansion based on the assumption that cross terms (like s12) are much smaller than the diagonal terms (like ...
• 1,055
59 views

### I want to represent the function based on specific variables in Mathematica

I have a function call S11 and I want the formula simplified with variables: Q, k, wn. But I new with Mathematica, don't know how to do it. And I can't find the function doing this. Please help me ...
63 views

### Issue solving a recurrence relation

I´m trying to solve the following recurrence relation in Mathematica: ...
• 145
41 views

### Issue solving recurrence relation

I´m trying to solve the following recurrence relation: ...
• 145
303 views

### Problem computing a limit

I have the following function in Mathematica: $\frac{x! \sum _{i=1}^j (-i+j+1) S_{j+1}^{(-i+j+2)} x^{-i+j+1}}{(x-j)! \left((1-x)_j\right){}^2}$ Defined as: ...
• 145
1 vote
67 views

### How to verify a FactorialPower identity?

How to verify that FactorialPower[x, m*n, k] is always the same as Product[FactorialPower[x - i*k, n, m*k], {i, 0, m - 1}] ...
126 views

### Minimize the number of components in the output of Reduce

Reduce typically tries to minimize the number of components used in describing a region, but it sometimes fails, as in the following example: ...
• 327
222 views

### Summation not returning a timely result

Why is Mathematica v12 spinning on this series: FullSimplify[Sum[16^x/((16^x) + 4), {x, 1/2025, 2024/2025, 1/2025}]] The answer works out to 1012. Is there another ...
• 637
168 views

### Power of multiplication of powers

I have an issue where I want to compute ((-1 + a^2)^2 (-1 + b^2)^2)^(1/4) which should evaluate to Sqrt[(1 - a^2) (1 - b^2)] if ...
• 41
37 views

### Issue with simplifying an expression with "ConjugateTranspose"

Why does the output [6] have Conjugate in it even when I explicitly mention that $c>b$ and all other parameters are real? ...
• 243
73 views

### How to simplify the root of $\sqrt{-x^2-y^2-z^2}$?

in Mathematica, how can I perform the following simplifying? $$1/\sqrt{-x^2-y^2-z^2} \rightarrow 1/(i \sqrt{x^2+y^2+z^2}),$$ where $x,y,z$ are reals numbers and $i$ is the imaginary unit.
• 133
128 views

• 3,410
1 vote
106 views

### How to sort the terms in a polynomial according to their degree?

I have the polynomial ...
• 281
206 views

### Why does FullSimplify crash the kernel?

Bug introduced in 13.2 or earlier and fixed in 14.1 Save your work before attempting. I realise this may get fixed in later versions – I am more interested in the why. On OSX 14.4 and Mathematica 13.2 ...
• 9,787
82 views

### Simplifying Min with assumptions

Lots of ecological models use Liebig's law of the minimum when multiple essential resources may limit growth. I want to break these equations into the special cases using ...
• 20.3k
154 views

### Specifying properties of a function as assumptions

I am trying to simplify expressions involving a function $f: \mathbb C \to \mathbb C$ which satisfies $$f(-z) = -f(z), \quad f(z^*) = f(z)^*, \quad \forall z \in \mathbb C.$$ I do not want to specify ...
• 143
40 views

### Extracting matrix coefficients from multivariate matrices

Suppose we have a multivariate polynomial matrix $P(\mathbf x) = \sum_\alpha A_\alpha\mathbf x^\alpha$ (in multi-index notation) where the $A_\alpha$ are constant coefficient matrices. I am looking ...
1 vote
83 views

### Simplification of expression with PolyLog[4,2]

I am trying to simplify the following expression. expr=1/2 \[Pi]^2 Log[2]^2-2/3 I \[Pi] Log[2]^3-4 PolyLog[4,2]+7/2 Log[2] Zeta[3] This ...
• 1,897
1 vote
84 views

### Separation of variables

Is it possible to replicate the same procedure of placing the functions that depend on $r$ on one side of the equation and on the other side leave the equations that depend on $\theta$ in Mathematica? ...
• 157