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visits member for 4 years, 6 months
seen Jun 24 '13 at 0:06

No, his mind is not for rent
to any god or government.
Always hopeful, yet discontent.
He knows changes aren't permanent,
but change is.

— Rush, Tom Sawyer


Taking an externally-imposed and much-needed break from SE activities.

E-mail (flipped ROT13): zqd˙ʎʌuzʇ@ʇɐʌǝɥʇʌssqɹǝɥɟuɹʎɔ
Any code I've posted here I place under the WTFPL.


Sep
20
comment How to start with mathematics?
"Pick one book and persevere with it." - Not always the best idea I think; trying to stick to a really sucky book can be damaging. And sometimes it's hard to tell what's crappy and what ain't when you're just getting started.
Sep
20
comment Is there any formula for the series $1 + \frac12 + \frac13 + \cdots + \frac 1 n = ?$
Well, there's the digamma function, but it's still cheating I think. :)
Sep
20
comment Is there any formula for the series $1 + \frac12 + \frac13 + \cdots + \frac 1 n = ?$
And mathworld.wolfram.com/HarmonicNumber.html too.
Sep
20
comment What are we solving with row reduction?
I totally agree with most of this answer except the use of the adjective "lowbrow"; if nothing else, Gaussian elimination is nothing but a tidy, systematic reorganization.
Sep
20
revised Calulating length of cable running along exterior of an axle
corrected formula
Sep
20
answered How to start with mathematics?
Sep
20
revised Calculating Intersections of Lines and Algebraic Surfaces
grammar
Sep
19
revised Calculating Intersections of Lines and Algebraic Surfaces
additions
Sep
19
comment Area of a quadrilateral
@Dario: Oh, then I'm in complete agreement, then. :)
Sep
19
comment Area of a quadrilateral
@Dario: so far as I can tell none of the answers thus far has given an explicit solution; I suppose nothing here can be construed as spoonfeeding.
Sep
19
answered Calulating length of cable running along exterior of an axle
Sep
19
comment Calculating Intersections of Lines and Algebraic Surfaces
The cube is nothing more than six planes; just treat the six planes as a group. What sort of examples would you want to see?
Sep
19
comment Interesting results easily achieved using complex numbers
I don't like memorizing formulae either. +1 :D
Sep
19
comment Limit of Gamma integrals
Brilliant! This is much neater than what I was trying. :)
Sep
19
comment Calculating Intersections of Lines and Algebraic Surfaces
@dimo: Exactly what other shapes did you have in mind that you say are giving you trouble? As I said, dealing with arbitrary algebraic surfaces is a tough one; the examples you gave are so-called "quadric surfaces", and these are relatively easier to handle/parametrize/manipulate.
Sep
19
revised Area of a quadrilateral
additional
Sep
19
answered Area of a quadrilateral
Sep
19
comment Calculating Intersections of Lines and Algebraic Surfaces
As for doing the intersection of two algebraic surfaces, the highbrow way of going about it relies on Gröbner basis computations, but that's too much I think for a simple class project.
Sep
19
answered Calculating Intersections of Lines and Algebraic Surfaces
Sep
19
answered Perpendicular bisector