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#1353 Re: Help Me ! » Extremely complicated change of a volume formula » 2005-12-30 23:10:57

I was right from the begining!
If x=Root[a == b x^2 + c x^3,1](means the first root of f(x)) then Im[x]->0!

#1359 Re: Help Me ! » Extremely complicated change of a volume formula » 2005-12-30 21:59:51

I'm sorry. Actually this runction has three roots.
1-real and 2-complex.
Here's it's roots:

#1363 Re: Help Me ! » Help with 3D rotation » 2005-12-30 13:00:42

If we use polar coordinates is easy:
Let A= (r, alfa)pol
Then
A'= (r,alfa+45 deg)pol= (r,alfa+(1/8)2Pi rad)pol= (r,alfa+Pi/4)pol.
Now from decart c.s. to polar c.s.:
Let A= (x,y)dec
r=sqrt(x^2+y^2)
cos(alfa)=y/r
alfa=arccos(y/r)=arccos(y/sqrt(x^2+y^2))

Then
A'= (sqrt(x^2+y^2),arccos(y/sqrt(x^2+y^2))+Pi/4)pol
Now from polar to decart:

x'=r'*sin(alfa')=sqrt(x^2+y^2)*sin(arccos(y/sqrt(x^2+y^2))+Pi/4)
y'=r'*cos(alfa')=sqrt(x^2+y^2)*cos(arccos(y/sqrt(x^2+y^2))+Pi/4)

#1364 Re: Help Me ! » Help with 3D rotation » 2005-12-30 12:41:05

We must find the equation of the line in the coordinate system, roated 45 degrees ++clock:

#1366 Re: Help Me ! » Help with 3D rotation » 2005-12-30 12:28:01

You can't integrate it exactly.

#1367 Re: Help Me ! » Help with 3D rotation » 2005-12-30 12:17:07

Is this write?
I just orbitained it:

#1369 Re: This is Cool » vector multiplicated by i » 2005-12-30 11:39:34

So the vector multiplicated by i becomes a vector with negative length!

#1372 Re: Maths Is Fun - Suggestions and Comments » Some more Javascript Games » 2005-12-30 10:37:07

I prefer VBScript.
Here's a game as html page:
crazy machine.htm

#1373 Re: Help Me ! » Simplifying Monomials Help (Algebra 2) » 2005-12-30 10:21:21

2) It is not monomial It cannot be simplified:

#1375 Re: Help Me ! » Equation help » 2005-12-30 10:10:18

You'll learn a lot from us.

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