_llll_ | true but useless any set is dense in itself... |

Kampen | Q isn't always dense in R :p depends on the topology |

TRWBW | i guess you could come up with a definition A is dense in B in C if B is contained in closure of A in C |

_llll_ | it would be Q if it didnt have the subspace topology s/would/wouldnt/ |

TRWBW | but it wouldn't be standard |

Kampen | the definition of dense i usually use is if A is contained in B, and B is contained in cl(A), A is dense in B subspace topology? what's the base for that? is that the discrete? |

TRWBW | that's the induced topology |

Kampen | ah, ok |

pirothezero | lin. algebra question: change of bases of P C<-B = ( P B<-C)^-1 correct?? |

TRWBW | pirothezero: don't know the notation, but inverting is the right idea |

pirothezero | alright cause i am working on this one where i got P B<-C as 2x2 [1,2,4,9] and it says the change is [9,-2,-4,1] but when I run the inverse formula i get [9,-4,-2,1] |

godtvisken | Pi should be equal to the limit as s approaches infinity of (s*sqrt(2-2cos(360/s)))/2 right? i get an accuracy of 7 places when s=9500, but when s=9600 an accuracy of only 6 places. why is this? maybe a limitation of my calculator? |

TRWBW | pirothezero: you are using odd notation. no one else on the planet who isn't taking the course from your teacher is going to know what you mean unless you define everything godtvisken: yes, but you can improve that |

godtvisken | TRWBW: ? |

TRWBW | godtvisken: the problem is the 2-2cos, you are substracting two numbers that are almost identical godtvisken: so you get very little precision, and less precision the bigger n gets godtvisken: you need to rewrite it using trig identities |

godtvisken | aha |

pirothezero | okay the 2x2 matrix notation i put means in [1,2,4,9] first row is 1,2 2nd row is 4,9. And P B<-C means change C to B |

benkillin | Trig identities are the boss |

pirothezero | doesnt seem like that helps a whole lot though |

ailndx | http://library.thinkquest.org/J0110961/2diga.gif is it possible to write like this in latex? |

TRWBW | pirothezero: what does change C to B mean? |

masquerade | pirothezero, you might have more luck getting people to understand [[1,2][4,9]] for matrix notation |

benkillin | OH ! I get it now |

KRUSHGROOVE | pirothezero, or you could also write [a,b;c,d] |

pirothezero | change of coordinates matrix from B to C |

TRWBW | pirothezero: you can say that a million things and it doesn't mean anything |

godtvisken | TRWBW: well, i am using the law of cosine, and assuming the line from the center to the corner of the polygon with n sides is 1 (a circle with a radius of 1 is what the shape should approach) |

gordboy | maybe the calculation of cos near 0 isn't as good, also |

pirothezero | multiplication by P C<-B converts Bcoords into C coords |