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visits member for 2 years, 9 months
seen Apr 29 '13 at 17:50

Apr
7
comment Given a random sequence give a recurrence defining it.
Might this be possible with some application of interpolants?
Nov
25
comment Electric dipole potential (Taylor expansion)
thank you for all your help, cleared it up a lot!
Nov
25
comment Electric dipole potential (Taylor expansion)
I know how to obtain the Taylor expansion of that. From your answer the lecturer neglects the $s^2$ term since $s\to 0$, then takes out a common factor or $\dfrac{e}{r}$ to get $-\dfrac{e}{r} (-1 + \dfrac{1}{\sqrt{1- \dfrac{2xs}{r}}})$. I understand how to get here, but then the lecturer rearranges this to obtain $\dfrac{e}{r}\left[ -1 + (1+\dfrac{xs}{r^2})\right]$. This bemuses me.
Nov
25
comment Electric dipole potential (Taylor expansion)
Ah, I see, so that's not the Taylor expansion at all. The Taylor expansion must come in the line she writes after this (sorry, was confused about this, don't see why she had to write ellipsis so presumed that was the expansion!). Please see my edit.
Mar
7
comment Continuity with normed spaces
Why can we assume that $\delta \le 1$?
Mar
7
comment Continuity with normed spaces
My apologies, I've fixed that (the $f+g$ was from the previous question in the book).
Feb
29
comment Cauchy sequence
Oh, that rings a bell, I remember reading that a coefficient doesn't matter and we like to have just $\epsilon$ "for cosmetic reasons". Thanks.
Feb
29
comment Complete normed spaces
Why can you say that $||x-y||\le \frac{1}{c_{1}}$?
Feb
29
comment Sum of Cauchy sequences
I tried the triangle inequality, how're you supposed to go backwards with it to get it into the form desired?