# Questions tagged [simplifying-expressions]

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

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153 views

### How to reduce this binary polynomial to the sum of squares in various ways

I can convert this binary polynomial to the sum of the squares of multiple polynomials using the following method: ...
220 views

### Incorrect Result from DSolve for Diffusion IBVP?

The result of DSolve for the following IBVP doesn't seem to satisfy the IBVP: \begin{cases} u_{t} - ku_{xx} = 0 &\mbox{} k>0,x>0,t>0 \\ u(0,t)=p(t) &...
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### Reducing large polynomial expression to product of simplar polynominals

A beginner to Mathematica. I am trying to express a large symbolic polynomial expression as a product of factors of simpler polynomials: For example I was able to factor this expression: ...
44 views

### Applying the command “expr/.rule”, to find the expansion of Cos[a+b]

how can i find the expansion of Cos[a+b], using the expression g[f[{a,b}]].So i am specified to use one shot replacement to get the expansion by replacing the argument of the expression given. I tried ...
51 views

### Simplify multiple layers fractions

I have a complicated fraction ...
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### How do I get from a few sub equations to a final equation?

I have a few start equation like Z1 and Z2 in the S domain. How can I use Mathematica to get the final equation? Including the index numbers?
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### Why does Mathematica give exact solution 0 for this indeterminate expression?

I have this function: $\frac{(1-\cos (\theta ))$ and I want to know its value for $x=\pi$, $\theta=0$ and $n\in\mathbb{N}$. It is clear that both numerator and denominator are zero, so the result ...
112 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. ...
33 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. ...
86 views

### Finding the value of an expression [closed]

Here is an expression that can be easily shown to equate 2 by analysis. $$\sqrt{7+\sqrt{50}}+\sqrt{7-\sqrt{50}}$$ But no matter what i try Mathematica always shows a complex result:2.62132 + 0....
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### 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: ...
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 ...
45 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: ...
77 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 ...
93 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 ...
64 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 ...
55 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. ...
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 ...
42 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 ...
106 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 ...
28 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 ...
34 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 ...
31 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 ...
64 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 <...
46 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 ...
77 views

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] ...
55 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: ...
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})} ...
86 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? ...
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 ...