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Questions tagged [assumptions]

Questions about the function Assuming[], the $Assumptions system variable, and the Assumptions option of functions such as Simplify[] and Integrate[].

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5
votes
2answers
207 views

Well-defined symbolic integral leading to ConditionalExpression

I would like to determine a closed-form expression for the following symbolic integral $$ \int_{-1/2}^{1/2} \!\!\!\! \mathrm{d} x \int_{-1/2}^{1/2} \!\!\!\! \mathrm{d} y \, \frac{1 + b x + c y}{1 + e ...
4
votes
3answers
310 views

Using Assuming with Reduce

I have the following code that includes Assuming to cut through irrelevant detail, or so I had hoped. ...
4
votes
1answer
280 views

How to use Assuming and If together?

I would like to compare variables t and u and print either Yes or ...
4
votes
4answers
7k views

How to take conjugate of a function?

Naïvely this is what happens and it obviously is not helpful! ...
4
votes
1answer
274 views

Why does Assuming for Integrate not work as expected?

I'm trying to perform the following integral with Mathematica 7: ...
4
votes
1answer
241 views

Integrate: Mathematica does nothing, not even repeat the code!

I need to calculate the following integral: $$ \int_{-\infty}^{\infty}da\int_{-\infty}^{\infty}db\int_{-\infty}^{\infty}dx\int_{-\infty}^{\infty}dy~e^{\frac{-(b^{2}+(a-10g)^{2})}{g^{2}-1}}e^{\frac{-(...
3
votes
3answers
162 views

How make D[f,x] treat OverBar[x] as a constant

I have an expression of the form f = a*x +OverBar[x], where OverBar[x] is just a name, it has not much to do with the variable x. I want ...
2
votes
1answer
115 views

Problem with SeriesData

Problem: I need to find the leading order term in an expansion whose leading order behavior is a priori unknown. I can of course go with Series and try different orders, say ...
2
votes
3answers
1k views

DSolve will not apply assumption m ∈ Integers

I am trying to solve a linear second order ODE using DSolve which involves an arbitrary integer m. ...
2
votes
0answers
51 views

How to express continuity assumption for Integrate?

I am wondering if it is possible, and how if so, to express function continuity in the assumptions for the definite form of Integrate. First of all, while ...
2
votes
2answers
183 views

How to Integrate the Derivative of a function with Assumptions on the function?

I have a monotonic increasing function g and constant αsuch that ...
2
votes
1answer
43 views

Verifying $F(A)\subset B$ numerically and symbolically for a complex function $F$ with assumptions

As it is mentioned in a previous question of mine, one can construct a holomorphic bijection between the (open) unit disc $D=\{z\in{\bf C}: |z|<1\}$, and a domain $D\setminus\overline{B_{1/2}(-1/2)}...
2
votes
0answers
330 views

Piecewise functions Integration with symbol

I want to integrate one piecewise functions as following, ...
1
vote
1answer
80 views

Assuming that only the 2nd order terms are zero

I am dealing with first-order perturbative theory, that is, any variable may be decomposed as $a = a + \delta a$ and the same would occur with several different variables, let's say, $b$ and $c$. ...
1
vote
1answer
143 views

Simplifying using assumptions

Is there a way to simplify the following equation (-p(a-x)((a-b)P(b-x)+Q(b+x)(a-b+2x))+q(a+x)(-(a-b)Q(b+x)+P(b-x)(-a +b+2x)))/((b-x)(-a + x)(a+x)(b+x)) assuming ...
0
votes
1answer
293 views

How do I declare that a variable represents a real number? [duplicate]

How do I tell Mathematica that a variable is a real number. I searched for this question here and in Google and nothing that was suggested seems to work for me. I must be missing something. My code is ...
0
votes
1answer
135 views

How to find analytical solution for integral from product of Bessel functions of second kind with different order?

I need help with analytical solution for the following integral: ...
0
votes
2answers
788 views

Integrating hat functions

I am trying to integrate a hat function for a project that I am doing and have found a method to do so but I find it sloppy. Currently I have the basis function ...
0
votes
1answer
327 views

Re[x] vs. x ∈ Reals in the context of Assuming

Let's say that $x$ is some real valued number $>0$. Are the following commands interchangeable in the context of using Assuming? ...