Hi,
SMath can find a "symbolic" soluction for yor equation using "Ctrl+." :
a:1
b:2
c:3
d:4
F(x)←(a+b*(x/V)+c*(x/V)^2+d*(x/V)^{-2})
don't use "=" for asking for F(100*V)
use "Ctrl+." instead:
F(100*V)—75502501/2500

Then copy the "symbolic" answer and use "=" to find:

75502501/2500=3.02*10^4

Regards,

Oscar Campo

Hello asdfghjkl

I do not quite understand you, sorry. I would suggest you to use SMath and math tags - not the text:
For instance,
Instead of using:

a+b(x/V)+c(x/V)^2

Use this, by math tags and copying from SMath - like this:

a+b*(x/V)+c*(x/V)^2

(see the Wiki pages and Notes of how to use the Forum, please).

However, I would try to be a "mind reader" regarding your question.
In the previous posts, there was the advice to avoid using units in some complicated functions - errors are easy to make.
Now, you tried to use integration with the functions and variables having units. Let's try it. First of all, you should know that SMath does not do the symbolic integration - only numeric. Moreover, I think it does not work well with units.

Here is an example, similar to your request (I hope):

Function F(x) might represent a specific heat function receiving "x" in unit temperature (Kelvin) and returning the result in unit (BTU/(mol*K)). Now, you will try to calculate enthalpy "Y" by integrating specific heat over a temperature range (say from 300 to 800). It worked, but it is a bit confusing because we forced the integration to use units - the result should be in (BTU/mol).
For comparison here is the same calculation performed in Mathcad


To repeat the advice from my own experience - try to avoid units for complicated calulations. Units are quite safe and useful to use when you have the basic algebraic operation - addition, substraction, multiplication, division and raise to power.

Regards,
Radovan

Edited by user 13 October 2010 12:40:21(UTC)  | Reason: Not specified