Using solve and sigma from programming

[roadrunner]

I deleted my previous post because i had an error in the program.

I'm thinking this:

PHP Code:

EXPORT testsum()
BEGIN
 LOCAL pv,cf,result;
 pv:=100;
 cf:=10;
 result:=CAS(EVAL("solve("+pv+" = (sum("+cf+"/(1+r)^n,n,0,∞)),r)"));
 return result;
END; 


is what you are looking for?

-road