# Tagged Questions

How to manipulate expressions structurally, not necessarily complying with the rules of algebra.

435 views

### How can I see which transformations Simplify attempts?

The documentation for Simplify[expr] says that it performs a sequence of algebraic and other transformations on expr, and returns the simplest form it finds. How can I see which transformations it ...
5k views

### How to expand tan(x+y) as normal form?

TrigExpand@Tan[x + y] gives $\frac{\sin (x) \cos (y)}{\cos (x) \cos (y)-\sin (x) \sin (y)}+\frac{\cos (x) \sin(y)}{\cos (x) \cos (y)-\sin (x) \sin (y)}$ but I ...
1k views

### How to manipulate gauge theory in Mathematica?

I want to know if there is a way of typing into Mathematica an expression like the following, \epsilon^{\mu \nu \lambda} f^{abc} A^a_\mu A^b_\nu A^c_\lambda + g\epsilon^{\mu \nu \lambda} A^a_\mu ...
744 views

### Comparing two symbolic expressions

Does Mathematica provide any way to compare two symbolic expressions and find which is the greatest? For example, I want to find which is the greatest of ...
308 views

### Construct an infix operation from a list

Inspired by this question, if I have a list {a, p, b, q, c} where p and q are binary ...
344 views

### Can mathematica simplify an expression setting simplified answer equal to zero?

Basically I want to reduce something like: Subscript[P, 4] - Subscript[P, 5] == Subscript[R, 4, 5]* Subscript[i, 4, 5] when only one of them is known (...
180 views

### Why doesn't Log[Gamma[]] simplify to LogGamma[] where it could?

I have been playing with various equations involving amount of permutations in relatively large sets. Easiest way to look at these is something like Log[10, bignumber!] . Often expressions, even ...
513 views

### Transform an expression into a graph that can be plotted with TreeGraph (not TreeForm)

I would like to plot an expression (like TreeForm does), but using the new TreeGraph functionality. ...
219 views

### Change values in equation with slider

I want to make an equation where the values adjust to my slider which I inserted with manipulate. Well, I tried, but when I use the slider the equation starts to fall apart. Actually this should ...
133 views

### Subvalue and level

I'm interested in the arguments of f in expressions like f[a]@f[b]@f[c] By argument I mean what is here ...
136 views

### How to prevent substitution?

I have a function: $\bar{u}:=u[t,x,y,z]$ (1) How do I prevent it from expanding and substituting in instructions like those following: $\partial _t {\bar u}$ (2) Thanks in advance EDIT: ...
420 views

### How to manipulate nested expressions?

I have the following expression, only slightly complicated, and I'd like to do two things: Plot the elements of the lists (though messy, all are in the same ...
745 views

### Google Code Jam: Mountain View code review

After participating in Google Code Jam 2012 Round 2, it occurred to me that the Mountain View problem boiled down to solving a set of linear inequalities, which could be done in Mathematica. I've only ...
787 views

### Displaying a series obtained by evaluating a Taylor series

Description of problem I would like to use Mathematica to display the series obtained by substituting a value for $x$ in a Taylor series expansion. The terms of the series will be rational numbers, ...
784 views

### How can I completely ban usage of some functions in output and mandate use of others?

For example, I hate that Mathematica uses Pochhammer symbol in outputs and prefer all the expressions in Gamma function. How can ...
524 views

### Extracting equations from Piecewise expressions

Say I have a PDF: PDF[LogNormalDistribution[1.75, 0.65], x] Calculating it, Mathematica gives me an expression that looks like this: I want to extract the ...
1k views

I have been working on picking expressions apart using Head and Part and encountered a little mystery. Consider the canonical ...
2k views

### Replacement inside held expression

I wish to make a replacement inside a held expression: f[x_Real] := x^2; Hold[{2., 3.}] /. n_Real :> f[n] The desired output is ...