Re: Binomial Expansion Program For TI-85


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Re: Binomial Expansion Program For TI-85



Althoug it is not a program that will display the entire thing so that
all you have to do it copy it down, the ti-85 does have this capability
(as well as most graphing calcs).  In any binomial expansion, each
coeffiecient comes from pascals triangle:

    1
   11
  121
 1331
14641
  ...
ok, great, what does that have to do with the 85, you ask... well,
pascals triangle is made up of combinations,like this

                                              ncr(0,0)
                                      ncr(1,0)  ncr(1,1)
                                  ncr(2,0) ncr(2,1) ncr(2,2)
                             ncr(3,0) ncr(3,1) ncr(3,2) ncr(3,3)

okay, what does that mean, you ask.  Well, to expand a binomial the
equation is like this

(a+b)^n   =
(ncr(n,0)*a^n*b^0)+(ncr(n,1)*a^n-1*b^1)+(ncr(n,2)*a^n-2*b^2)+(ncr(n,3)*a^n-3*b^
3)+....+((ncr(n,n)*a^0*b^n)

but you probably already knew that and I have wasted my time, but in
case you didn't here it is

when the equation has coeffecients in the problem, like (3a+5b)^5, you
just multiple the coeffectents.

oh yeah, the format for combinations on the 85 is (n NCR r), not
(ncr(n,r)), so make that adjustment.  hope this helps

Tim Brierley
brierley@erols.com



Dan Auvil wrote:

> I know the TI-85 does not do much in the way of symbolic algebra,
> but does anyone have a program for the expansion of a binomial
> (positive
> integer exponents only).  Any help would be appreciated!
>
> Dan


References: