# Tagged Questions

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

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### FullSimplify does not distribute Abs over multiplication

FullSimplify[Abs[x]^2, x \[Element] Reals] reasonably returns x^2, but the barely-more-complicated expression ...
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### Simplfying with Log and Exp functions

Short question, I have: $\log \left(0.617424 e^{-1.19761 (W-0.427026)^2}\right)-\log \left(0.617424 e^{-1.19761 (0.116019\, -W)^2}\right)$ W is real and ...
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### Difficulties in algebraic simplifications

I am a new user, and I am a bit puzzled while experimenting with Mathematica functions, their derivatives and derivatives of functions. I have an expression such as: ...
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### I have a term 'Keff' in terms of 'W'. I need to write 'W' in terms of 'Keff'. Does Mathematica provide an option for that

I have read similar answers on this topic. I am still not able to execute my code.The code is as follows. ...
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### Getting mathematica to factor out constants and apply euler's identity to a table

I'm doing some quantum mechanics homework that I'm going to eventually generalize to higher spin states, so the solutions are going to need to be decently independent of the dimensions of the table ...
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### How can I prevent exponents from appearing in an expression?

I've found posts dealing with showing/hiding exponents for numbers, like in scientific notation. But what if I have a general expression? I have an expression like this, ...
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### Simplify the following transformed equation [closed]

y=7f(-1/6(x-1))+1 The base function is f(x)=x^2. I just don't understand where the ^2 went and how to simplify this. Any help is much appreciated, thanks.
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### Factoring rationals from equation based on digit complexity?

Consider an equation of the following type: ( poly = (3 x)/35 + (6 y)/7 ) == 0 If we apply the command Factor to this ...
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### Simplify not working for a real part of a complex expression [closed]

When I try to get the real part of a term, for example: $\qquad \Re\left(\frac{e^{-i k} \left(2 k^2+\pi ^2 \left(-1+e^{i k}\right)\right)}{\pi ^2-k^2}\right)$ Mathematica will output the same thing ...
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### Extract coefficients from trigonometric polynomial [closed]

Suppose I have: f[r_, ϕ_] = C1 Cos[ϕ]r + C3 Sin[3 ϕ] r + C4 Sin[4 ϕ] r^4; How do I extract the coefficient of a chosen trigonometric term, let's say ...
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### Reliable testing of identities (example: modular functions)

Take, for illustration, the following function (bonus points for anyone who identifies where it comes from!), defined on the upper half plane: ...
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### How to combine similar terms in a density matrix expression? [Ref: Quantum Computing]

I tried the following : Simplify, FullSimplify, and Expand. Due to this problem, I am not ...
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### Running out of memory when doing non-commutative arithmetic

I need to calculate particular coefficients of the composition of two power series in non-commutative variables. The code below which works fine truncates power series in degree $n=5$. For $n=6$ (the ...
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### Dealing with indicator functions

I am calculating the integral of two indicator functions with Mathematica. I'm having difficulty in imposing assumptions. What I have done so far: To define an indicator function: ...
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### FullSimplify does freaky things with approximate Gaussians [duplicate]

I was playing around with Vitaliy Kaurov's neat answer to this question, and found something a bit unusual: ...
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### DiracDelta of a function

If I have, for instance, FunctionExpand[DiracDelta[x^2+x-3]] it evaluates to ...
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### Series: two varibles, how to eliminate the (product) higher order

I have a function of $f(x,y)$, where $x,y$ are very small numbers. I want to series expand it to the $3$rd power. However I don't want the terms such that $x^2y^2$, $xy^3$ etc. because I would reckon ...
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### Reduce excess Log[] [closed]

I am trying to solve a differential equation using DSolve: DSolve[y'[t] == t^10 eps^-y[t], y[t], t] And get the following output: ...
180 views

### Separate variables in equation

I need to know is there a way to separate the desired variables in the equation at one side of the equality. For instance, the following equation ...
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### Need help simplifying final expression [closed]

I was carrying out a function and ended up with the desired answer, but for some reason, Mathematica keeps giving me the answer in a strange numerical form. ...
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### How to replace $-x^{}\,y^*-y^{}\,x^*$ by $-(x^{}\,y^*+y^{}\,x^*)$?

Up to now, I have tried some codes like the following: ...
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### Simplifying symbolic expressions using TensorExpand

Following my previous question I have this issue using TensorExpand: KroneckerProduct[x, y].(KroneckerProduct[2 z, w]) // TensorExpand results in ...
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### How to write an expression in the desired form?

I have the following code: ...
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### Is it possible to simplify an expression in vector form, which involves crossproduct and dot product?

I often need to simplify expressions involving cross product and dot product, for example: f = Dot[Cross[Cross[p1 - p, e1], Cross[p2 - p, e2]], Cross[p3 - p, e3]] ...
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### Simplification of products of KroneckerDelta[]

What is the reason why the following expression does not simplify to True? ...