MathGroup Archive 1996

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

Search the Archive

Re: Will you please help a non-mathematician?

  • To: mathgroup at
  • Subject: [mg5606] Re: Will you please help a non-mathematician?
  • From: pecora at (Lou Pecora)
  • Date: Fri, 27 Dec 1996 23:43:38 -0500
  • Organization: Naval Research Lab
  • Sender: owner-wri-mathgroup at

In article <59vp4j$f82 at>, DONKROUS at HALCYON.COM (Don
Krouse) wrote:

> Please be gentle, I'm not a mathematician.
> Solving the below equation for all variables, except i, works
> satisfactorily. Trying to solve for i produces the following result.
> in[1] Solve[0==PV+PMT*((1-(1+i)^-n)/i)+FV*(1+i)^-n,i]
> Solve::tdep: 
>    The equations appear to involve transcendental functions of
>     the variables in an essentially non-algebraic way.
> out[1] Solve[0 == FV/(1 + i)^n + ((1 - (1 + i)^(-n))*PMT)/i + PV, i]
> Can someone tell me how to get Mathematica to solve for i?

I think what MMA is telling you is that it _can't_ solve for i.  A quick
glance at your equation makes me think there is no algebraic solution. 
Typically, equations involving a variable _and_ exponentials of the
variable are unsolvable.  There are special case exceptions.  You really
need to find someone mathematical to look at your case and see if it can
be done.  Sorry, that wasn't much help.  The alternative is to use
numerical solutions.

Lou Pecora
code 6343
Naval Research Lab
Washington  DC  20375
 == My views are not those of the U.S. Navy. ==

  Check out the 4th Experimental Chaos Conference Home Page:


  • Prev by Date: Re: Weibull Distribution
  • Next by Date: How to get 2.334E+6 output form ?
  • Previous by thread: Will you please help a non-mathematician?
  • Next by thread: Interactive plotting in Mathematica?