## 155 Reputation

9 years, 157 days

## How to make the assumption?...

@Alejandro Jakubi

How does Mathematica integrate this equation?
(Sorry, I don't have Mathematica to try)

And, according to your disscussion, whether can I get the correct result if I make some assumption or definition in Maple? For example, I assume ln(0) = -infinity (if Maple can do this) and get the result " undefined if -100<n<-10, -ln|n+10|+ln|n+100| otherwise".

Or, I define some properties of parameters in the integral to make command int get the correct piecewise function?

Obviously, the option you use in command solve cannot to be used in command int. How to do this kind of assumption? I know the command asuume, but it seems that assume cannot do this job.

Thank you all :)

## Thanks...

@Markiyan Hirnyk Thank you for your help :)

## @Carl Love  Oh, so that's how it is...

Oh, so that's how it is. Thanks.

## @Carl Love  Thank you for your answ...

But for the first part, do you know the purpose of function "In-place operation"? Why the command Map want to change its arguments. It must to benefit some computation which I don't know about.

## @Carl Love  I only want to express ...

I only want to express the result is beyond my expectation, thanks, anyway.

## @mehdi jafari  OK!! I see!! Thank y...

OK!! I see!!

Thank you very very much~

## @Carl Love Thanks for your suggesti...

Thanks for your suggestion, I did notice another inconsistency:

T____T

## @Preben Alsholm  What I confused is...

What I confused is the fifth action of Maple in this example.

Why the map printed five outputs but accepted only four operands from the list (or vector)?

## @mehdi jafari  So... do you mean th...

So... do you mean the "[]" is not the operands from an expression?

Thank you Carl~

## Thank you :)...

That's cool. It's the first time I've heard of such a special method.

Thank you~ :)

@Carl Love

It's a very conveninet way that I've never thought of before.

<v> uses the vector v being a unit of the new vector and it's no doubt that it creates a matrix.

But "m[...,1]"...  It means the part of the matrix is not another matrix absolutely, for example:

m:=Matrix(3,1,[x,y,z]):

m1:=m[1..3,1]:

m2:=m[1..3,1..1]:

lprint(m1)

Vector[column](3, {1 = x, 2 = y, 3 = z}, datatype = anything, storage = rectangular, order = Fortran_order, shape = [])

lprint(m2)

Matrix(3, 1, {(1, 1) = x, (2, 1) = y, (3, 1) = z}, datatype = anything, storage = rectangular, order = Fortran_order, shape = [])

It's the other very interesting topic. Thank you.

Thank you for reminding me.

In some cases, it makes no sense to compute the mapping matrix and the vector space.

## Thanks...

Ok, it works now. Thank you for your kindly help :D

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