MathGroup Archive 2009

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: binomial expansion of quantity raised to power of

  • To: mathgroup at smc.vnet.net
  • Subject: [mg101643] Re: [mg101598] binomial expansion of quantity raised to power of
  • From: Bob Hanlon <hanlonr at cox.net>
  • Date: Sun, 12 Jul 2009 05:50:38 -0400 (EDT)
  • Reply-to: hanlonr at cox.net

It is the series expansion around h = 0

Simplify[
  Series[(s^2 - h^2)^(1/2), {h, 0, 7}], 
  s > 0] // Normal

-(h^6/(16*s^5)) - h^4/(8*s^3) - h^2/(2*s) + s

FullSimplify[
 SeriesCoefficient[(s^2 - h^2)^(1/2), {h, 0, 2 n}],
 {Element[n, Integers], n >= 0}]

(-1)^n*Binomial[1/2, n]*(s^2)^(1/2 - n)

Simplify[
 Sum[%*h^(2 n), {n, 0, Infinity}],
 s > 0]

Sqrt[s^2 - h^2]


Bob Hanlon

---- Roddye Davis <roddye at ca.rr.com> wrote: 

=============
I saw in an engineering survey book a binomial expansion of (s^2 - h^2)^(1/2) = s - (h^2/2s) - (h^4/(8(s^3)))....

How was this result achieved???????  Thanks.




  • Prev by Date: Re: binomial expansion of quantity raised to power of 1/2
  • Next by Date: Re: binomial expansion of quantity raised to power of 1/2
  • Previous by thread: Re: Add syntax highlighting to own command
  • Next by thread: Plot Label at bottom with quote marks